Chevrolet Corvette C3
The Chevrolet Corvette (C3) is a sports car produced
by the Chevrolet division of General Motors for the 1968 through 1982 model years. Corvette chief Zora Arkus-Duntov wanted a striking new Corvette;
although engines and chassis components were mostly carried over from the
previous generation, its body and interior were new. "Though initially
flawed, the 1968 like the 1958, would improve and mature into a car precisely
right for its time." The
so-called Shark was produced during one of the most troubled periods in America:
civil unrest, burgeoning federal guidelines, fuel economy and pollution
regulations, oil embargoes, rising fuel and insurance costs, runaway inflation, and a lingering recession. Through it all the
third generation Corvette continued to set new sales records with an all-time
high of 53,807 produced for the 1979 model year.
Milestones of Corvette C3
1968, 28,566 produced, based price: $4,663: New
body and T-top removable roof panels, new interior, engines carried over,
three-speed Turbo Hydra-matic replaces two-speed Powerglide as automatic
transmission option.
1969, 38,462 produced, base price: $4,780: First
year of the 350 in³ Small-Block; longer model year extended to December, 1969
due to delay in introduction of 1970 model; "Stingray" front fender
nameplates added, new interior door panels and inserts, 17-inch black-vinyl
steering wheel (replaced 18-inch wood-rim wheel).
1970, 17,316 produced, base price: $5,192: First year
for the LT-1 Small-Block and 454 in³ Big-Block; three-speed manual transmission
dropped and four-speed manual became standard with Turbo Hydra-matic available
as no-cost option with all engines except LT-1 350; posi-traction made standard
equipment; introduced along with all-new second-generation Chevrolet Camaro on
Feb. 26, 1970, new egg-grate metal front grills and fender grills, lower molded
fender flares, new hi-back seats & interior trim, new custom interior
option includes:leather seat trim, cut-pile carpeting, lower-carpeted door
panels & wood-grain accents.
1971, 21,801 produced, base price: $5,496: Significant
horsepower drops due to reduced compression ratios to meet GM corporate edict
requiring all engines to run low-octane unleaded gasoline; horsepower ratings
based on both "gross" and "net" figures with the former
based on engine hooked to dynometer while "net" ratings based on
horsepower as installed in vehicle with accessories and emission controls
installed.
1972, 27,004 produced, base price: $5,533: Horsepower
ratings now advertised in SAE net figures, last year for LT-1 engine, front
& rear chrome bumpers & removable rear window, last year for windshield
wiper door.
1973, 30,464 produced, base price: $5,561: 5 mph
front bumper system with urethane cover, pot-metal front grills (black with
silver edges), chrome rear bumpers unchanged, new design front fender ducts,
first year for radial tires (standard equipment), rubber body mounts, new hood
with rear air induction & under-hood insulation, new front-end (round)
emblem.
1974, 37,502 produced, base price: $6,001: 5 mph
rear bumper system with urethane cover to match last year's front bumper, new
recessed tail lamps and down-turned tail-pipes. 1974 is the only year with two
piece rear bumper cover with center-split. No gas lid emblem was used. Aluminum
front grills (all-black), new dual exhaust resonators, revised radiator cooling
and interior a/c ducts, integrated seat /shoulder belts in Coupe. Last year for
true dual exhaust, last year for big-block engine in a Corvette.
1975, 38,645 produced, base price: $6,810: First
year of Catalytic converter & single-exhaust, black (painted) bumper pads
front & rear, redesigned inner-bumper systems & one-piece rear bumper
cover, plastic front grills (all-black), amber parking lamp lenses (replaced
clear lenses on 73-74) new emblems, last year of C3 convertible.
1976, 46,558 produced, base price: $7,604: First-year
for steel floor-panels, cold-air induction dropped, new aluminum alloy wheels
option, new one-piece rear "Corvette" nameplate (replaces letters),
last year of "Stingray" fender nameplates.
1977, 49,213 produced, base price: $8,647: Black
exterior available (last year-1969), new design ""Corvette
flags" front end & fender emblems. New interior console and gauges,
universal GM radios.
1978, 46,776
produced, base price: $9,750: New fastback rear window, Silver Anniversary and
Indy 500 Pace Car special editions; Pace-car included sport seats &
spoilers-front & rear, limited option-glass t-tops; redesigned interior,
dash and instruments.
1979, 53,807 produced, base price: $10,220: Sport
seats (from previous year pace-car); front & rear spoilers optional, glass
t-tops optional; New interior comfort features; highest Corvette sales year to
date.
1980, 40,614 produced, base price: $13,140 Lightened
materials, new hood, front end with molded spoilers, rear bumper cover with
molded spoiler and new tail lamps, Federal government required 85 mph (137
km/h) speedometer; California cars powered by 305 V8 and automatic transmission
for this year only, last year for L-82 engine - (n/a with manual transmission).
1981, 40,606 produced, base price : $16,258: Production
is switched from St. Louis to new Bowling Green plant; 350 V8 returns in
California cars, last year for manual transmission.
1982, 25,407 produced, base price: $18,290: New
cross-fire fuel-injected L83, New automatic overdrive transmission; Collectors
Edition features exclusive hatch rear window - is one fourth of production.
Total 542,741 produced.
Mako Shark II Concept
The
Corvette C3 was patterned after the Mako
Shark II designed by Larry Shinoda. Executed under Bill
Mitchell's direction, the Mako II had been initiated in early
1964. Once the mid-engined format was abandoned the Shinoda/Mitchell car was
sent to Chevrolet Styling under David Holls, where Harry Haga's studio adopted
it for production on the existing Sting Ray chassis. The resulting lower half
of the car was much like the Mako II, except for the softer contours. The
concept car's name was later changed to Manta Ray. The C3 also adopted the
"sugar scoop" roof treatment with vertical back window from the
mid-engined concept models designed by the Duntov group. It was intended from
the beginning that the rear window and that portion of the roof above the
seats–be removable.
The "Shark" has the distinction
of being introduced to the motoring public in an unorthodox—and
unintended—fashion. GM had tried their best to keep the appearance of the
upcoming car a secret, but the release of Mattel's die-cast Hot
Wheels line several weeks before the C3's unveiling had a
certain version of particular interest to Corvette fans: the "Custom
Corvette", a GM-authorized model of the 1968 Corvette.
1968–1969
_Stingray_427_L36_001_7481.jpg)
For 1968, both the Corvette body and
interior were completely redesigned. As before, the car was available in either
coupe or convertible models, but coupes had new removable roof panels (T-tops) and a removable rear window. A soft
folding top was included with convertibles, while an auxiliary hardtop with a
glass rear window was offered at additional cost. Included with coupes were
hold down straps and a pair of vinyl bags to store the roof panels, and above
the luggage area was a rear window stowage tray. The enduring new body's
concealed headlights moved into position via a vacuum operated system rather
than electrically as on the previous generation, and the new hide-away
windshield wipers utilized a problematic vacuum door. The door handles were
flush with the top of the doors with a separate release button. "Sting
Ray" nameplates were absent on the new 1968 body, but Chevrolet still
advertised the car as a Sting Ray. Front fenders had functional engine cooling
vents. Side vent windows were eliminated from all models, replaced with
"Astro Ventilation", a fresh air circulation system. In the cabin, a
large round speedometer and
matching tachometer were positioned in front of the driver. Auxiliary
gauges were clustered above the forward end of the console and included oil
pressure, water temperature,ammeter, fuel gauge, and an analog clock. A fiber-optic
system appeared on the console that monitored exterior lights and there was no
glove box. The battery was relocated from the engine area to one of three
compartments behind the seats to improve weight distribution. New options
included a rear window defroster, anti-theft alarm system, bright metal wheel
covers, and an AM-FM Stereo radio. All
cars ordered with a radio, like the C2 cars, continued to be fitted with
chrome-plated ignition shielding covering the distributor to reduce
interference.
The chassis was carried over from the
second generation models, retaining the fully independent suspension (with
minor revisions) and the four-wheel disc brake system. The engine line-up and
horsepower ratings were also carried over from the previous year as were the 3
and 4-speed manual transmissions. The
new optional Turbo Hydramatic 3-speed automatic
transmission (RPO M40) replaced the two-speed Powerglide. The L30, a 327 cu in (5.4 L) small-block V8 engine rated
at 300 hp (224 kW) and a 3-speed manual transmission were standard,
but only a few hundred 3-speed manual equipped cars were sold. The 4-speed
manual was available in M20 wide-ratio or M21 close-ratio transmission
versions. The M22 “Rock Crusher”, a heavy duty, close-ratio 4-speed gearbox,
was also available for certain applications. The
engine line-up included the L79, a 350 hp (261 kW) high performance
version of the 327 cu in (5.4 L) small-block. Also available
were several variants of the 427 cu in (7.0 L) big-block V8, that taken together made up nearly
half the cars. There was the L36, a 390 hp (291 kW) version with a
Rochester 4-barrel carburetor; The L68, a 400 hp (298 kW)
motor with a Holley triple 2-barrel carb set up (3 X 2 tri-power); The L71,
generating 435 hp (324 kW) with a tri-power; The L89 option was the
L71 engine but with much lighter aluminum cylinder heads rather
than the standard cast iron. Then there was the L88 engine that Chevrolet
designed strictly for off-road use (racing), with a published rating of
430 hp (321 kW), but featured a high-capacity 4-barrel carb, aluminum
heads, a unique air induction system, and an ultra-high compression ratio
(12.5:1). All
small block cars had low-profile hoods. All big block cars had domed hoods for
additional engine clearance with twin simulated vents and “427” emblems on
either side of the dome. The new seven-inch wide steel wheels had F70x15 nylon
bias-ply tires standard with either white or red stripe tires optional. Rare
options were: L88 engine (80), J56 heavy-duty brakes (81), UA6 alarm system
(388), L89 aluminum heads (624).
In 1969, small block engine displacement increased from
327 cu in (5.4 L) to 350 cu in (5.7 L), though
output remained the same. All other engines and transmission choices remained
unchanged from the previous year, though the L30 base engine was now the ZQ3
and the L79 motor was redesignated the L46. All cars featured 8-inch-wide (200 mm) steel wheels (increased from 7 inches). Tire size remained
the same, although this was the first year for optional white lettered tires
and the last for red striped tires. Carried over from the previous year were
seven available rear axle ratios ranging from 2.73 to 4.56. Standard ratio
remained 3.08 with automatic and 3.36 with manual transmission. The optional Positraction rear axle, mandated on many
engine/gearbox combinations, was installed on more than 95% of the cars. "Stingray"
script nameplates appeared on front fenders, now one word, in contrast to the
“Sting Ray” name used previously. Exterior door handles were redesigned so the
finger plate would actuate the door, eliminating the separate release button.
Backup lights were integrated into the inboard tail lights, headlight washers
were added, and front grilles were made all black. Side mounted exhausts and
front fender vent trim were options for this year only. On the inside, revised
door panels provided additional shoulder room in the C3's tighter cabin and
headrests became standard. Steering wheel diameter was reduced from 16 to
15 inches to permit easier entry and exit, the ignition switch was moved from
the dash to the steering column, and map pockets were added to the dash area in
front of the passenger seat. Accounting for 57% of the cars, coupes with their
removable roof panels, began a trend of outselling roadsters. An extended production cycle due to a
labor dispute increased '69 volume. This was the last year for the L88 engine
and the only year for the ZL1 option, which offered an all aluminum
427 cu in (7.0 L) big-block engine listed at 430 hp (321 kW). Rare
options: ZL1 aluminum block (2), J56 heavy-duty brakes (115), L88 engine (116),
L89 aluminum heads (390).
_Stingray_427_L36_004_1522.jpg)
Car and Driver magazine wrote in October 1968, “The small-engine
Corvettes are marginally faster and extraordinarily civilized. The large-engine
Corvettes are extraordinarily fast and marginally civilized.”
1970–1972
In 1970, fender flares were designed into the body
contours to reduce wheel-thrown debris damage. New were egg-crate grills with
matching front fender side vents and larger squared front directional lamps.
The previously round dual exhaust outlets were made larger and rectangular in
shape. Interiors were tweaked with redesigned seats and a new deluxe interior
option combined wood-grain wood accents and higher-spec carpeting with leather
seat surfaces. Positraction rear axle, tinted glass, and a wide-ratio 4-speed
manual transmission were now standard. The 350 cu in (5.7 L)
base engine (ZQ3) remained at 300 hp (224 kW) and the L46 was again
offered as a 350 hp (261 kW) high performance upgrade. New was the
LT-1, a 350 cu in (5.7 L) small-block V8 engine delivering a
factory rated 370 hp (276 kW). It was a solid lifter motor featuring
a forged steel crankshaft, 4-bolt main block, 11:1 compression ratio, impact extruded pistons,
high-lift camshaft, low-restriction exhaust, aluminum intake manifold, 4-barrel carburetor, and finned aluminum rocker covers. The new engine, making up less than
8% of production, could not be ordered with air conditioning but was fitted
with a domed hood adorned with “LT-1” decals.
Motor Trend in May 1970, clocked an LT-1 covering the quarter
mile in 14.36 seconds at 101.69 mph and remarked, “There is Corvette
and there is Porsche. One is the best engineering effort of America, the other
of Germany. The difference in machines is not as great as the disparity in
price.”
A special ZR1 package added racing
suspension, brakes, stabilizer bars, and other high performance components to
LT-1 cars. Big-block selection was down to one engine but displacement
increased. The LS5 was a 454 cu in (7.4 L) motor generating
390 hp (291 kW) and accounted for a quarter of the cars. A second
big-block, the 460 hp (343 kW) 454 cu in (7.4 L) LS7,
was planned and appeared in Chevrolet literature but is not believed to have
ever been delivered to retail customers. A short model year resulted in a disproportionately low production
volume of 17,316, down nearly 60% Rare options: ZR1
special engine package (25), shoulder belts in convertibles (475), LT-1 engine
(1,287).
1971 cars were virtually identical in appearance to
the previous model inside and out. This was the final year for the fiber optics
light monitoring system, the headlight washer system, and the M22 heavy duty
4-speed manual gearbox. For the first time, air conditioning was installed on
most of the cars, with nearly 53 percent so ordered. Engines were detuned with reduced compression
ratios to tolerate lower octane fuel. The small blocks
available were the 350 cu in (5.7 L) base engine, which dropped
to 270 hp (201 kW), and the high performance LT-1, now listed at
330 hp (246 kW). The LS5 454 cu in (7.4 L) motor was
carried over and produced 365 hp (272 kW). Offered in ‘71 only was
the LS6 454 cu in (7.4 L) big-block featuring aluminum heads and
delivering 425 hp (317 kW), highest of the 1970-72 series, and could
be ordered with an automatic transmission. The ZR1 option was carried over for
LT-1 equipped cars and the ZR2 option, offered this year only, provided a
similar performance equipment package for LS6 cars, and restricted transmission
to a 4-speed manual. Rare
options: ZR1 special engine package (8), ZR2 special engine package (12), LS6
425-hp engine (188), shoulder belts in convertibles (677).
1972 was the last year for chrome
bumpers at both front and rear, the vacuum actuated pop-up windshield wiper
door, as well as the removable rear window common to all 1968-72 coupes. The
key activated anti-theft alarm system became standard. The increasingly popular
choice of an automatic transmission was installed in most corvettes for the
first time, with nearly 54 percent so equipped. This year SAE net measurement for horsepower was now utilized (away from the previous SAE gross
standard), and was largely responsible for the much lower engine output figures
such as the 200 hp (149 kW) rating on the standard
350 cu in (5.7 L) motor. This was the final year for the LT-1
engine, rated at 255 hp (190 kW), and the ZR1 racing package built
around it. Although the M22 HD 4-speed was no longer a Regular
Production Option, it continued to be fitted to cars
outfitted with the ZR1 package. The
LT-1 could now be ordered with air conditioning, a combination not permitted
the two previous years. The LS5 454 cu in (7.4 L) big block was
again available and came in at 270 hp (201 kW). Noteworthy is in ’72
the LS5 was not available to California buyers. This was the beginning of a trend
where Chevrolet restricted certain power train choices to Golden State buyers
due to that state's practice of applying more stringent emission (smog)
standards than mandated by federal regulations. Convertibles were a vanishing
breed by ‘72, and the Stingray
was no exception. It sold only 6,508 copies, amounting to 9% of the market,
placing it number three; it was
beaten by the number one-selling Cutlass Supreme, with 11,571, but
beat the Impala's 6,456 and the Mustang's 6,401. Rare
options: ZR1 special engine package (20), shoulder belts with convertibles
(749), LT1 engine option (1,741).
1973–1974
1973 started Corvette's transformation from muscle
to touring sports car. A Chevrolet advertisement headlined: "We gave it
radials, a quieter ride, guard beams and a nose job." Indeed, redesigned body mounts and radial
tires did improve Corvette's ride, and interior sound
levels were reduced by 40%. The
chrome rear bumper was essentially carried over from the previous year.
However, the chrome blade front bumper was dropped for the federally required
5 mph (8.0 km/h) standard for a light-weight front bumper system with
an inner transverse tube attached to the frame with two Omark-bolts-(special
steel fasteners which absorbed energy when a forming die, pushed back by the
bumper, was forced down their length), and an injection-molded urethane bumper
cover. The urethane nose was chosen over Chevy's other alternative, a more
protruding version of the previous metal bumper. The new urethane bumper
assembly added thirty-five pounds to the front end. Two 350 cu in (5.7 L)
small block engines were available. The base L-48 engine produced 190 hp
(142 kW). The L-82 was introduced as the optional high performance
small-block engine (replacing the LT-1 engine) and delivered 250 hp (186 kW).
The new hydraulic lifter motor
featured a forged steel crankshaft, running in a four-bolt main block, with special rods, impact extruded pistons, a higher lift camshaft, mated to special heads with larger valves running at a higher 9:1 compression, and included finned aluminum valve
covers to help dissipate heat. The L-82 was designed to
come on strong at higher RPM and
ordered with nearly 20% of the cars at a cost of $299.
Car and Driver on the L-82 in December 1972, “…when it comes to
making a choice, the L82 is the engine we prefer. Duntov and the other Corvette
engineers gravitate toward the big blocks because they like the torque. And
granted, the 454s will squirt through traffic with just a feather touch on the
gas pedal. But, to us at least, the small block engine contributes to a fine
sense of balance in the Corvette that is rare in any GT car, so rare that it
would be a shame to exchange it for a few lb.-ft. of torque.”
The 454 cu in (7.4 L)
LS-4 big-block V8 engine was
offered delivering 275 hp (205 kW) and 15% of the cars were ordered
so equipped. “454” emblems adorned the hood of big-block equipped Corvettes.
All models featured a new cowl induction domed hood, which pulled air in
through a rear hood intake into the engine compartment under full throttle,
increasing power (but didn't show up in the horsepower ratings). 0-60 times
were reduced by a second while keeping the engine compartment cooler. The new
tire size was GR70-15 with white stripes or raised white letters optional. An aluminum wheel option was seen on
1973 and 1974 pilot cars, and a few 1973s were so equipped, but withheld for
quality issues, and wouldn't be available until 1976.
Road & Track magazine stated in a 1973 road test: "For all
its age, size and compromises, if the Corvette is equipped with the right
options it is a pleasant and rewarding car to drive and this 1973 example was
one the best Corvettes we've ever driven."
For 1974, a new rear bumper system replaced the
squared tail and chrome rear bumper blades introduced in 1968 with a trim,
tapering urethane cover carrying an integral license plate holder and recesses
for the trademark round taillights. Underneath sat a box-section aluminum
impact bar on two Omark-bolt slider brackets similar to the system used in the
nose which allowed the Corvette to pass federal five-mph impact tests at the
rear as well as the front. The new rear design was quite beautiful, and more
up-to-date than the 60's shape that it replaced with the vast majority of
enthusiasts embracing the new design. For the 1974 model only, casting
limitations mandated left and right bumper covers with a vertical center seam.
The anti-theft alarm key activator was moved from the rear panel to the front
left fender. Tailpipes were now turned down as the new bumper cover eliminated
the tailpipe extensions.
Car and
Driver magazine said:
"...We think the front and rear together produce a 'molded' shape that
speaks of function rather than decor." Chevrolet commented on the new
tailpiece in the '74 Corvette sales brochure: “Take the styling. We wouldn’t
just change it for the sake of change. But when we made the rear bumper
stronger, we made Corvette’s rear styling look different. And, we think
better...”
A 1974 Stingray equipped with the L48
195 hp (145 kW) small-block was capable of 0-60 in 6.8 seconds; comparable to the 6.5 second time
of the 1968 small-block rated at 300 hp (224 kW); proof the 1972-74
Corvette engines had ample power regardless of reduced horsepower and net (bhp) ratings. The L-82 engine remained at
250 hp (186 kW) and the 454 cu in (7.4 L) LS4 dropped
slightly to 270 hp (201 kW).
Hi-Performance Cars magazine in a L48, L82, and LS4
comparison test, September 1973, said: "Our choice for the all-around best
performer must go to the base 350 L48 engine...The L48 delivers all the
acceleration you'll ever need on the road in a steady, forceful manner...in addition
it runs cool, idles smoothly, and can cruise all day at 100 mph
(160 km/h). The L48 took 6.8 seconds to reach 60 mph
(97 km/h), the L82, 6.7 seconds and the LS4 454, 6.4 seconds. On
the Bridgehampton road course and over the ride and handling course at Suffolk
County Raceway, the base L48 coupe was again our choice...the L-82 had the same
balance as the L48 but if we weren't at the right rpm through a corner, or in
the wrong gear, the (L82's) lack of torque made itself felt once again...the
L48 was the best balanced of the three." In conclusion, they stated:
"The Corvette as a total concept has always been far more than the sum of
its individual parts. The fanatical clientele that buys 30,000 of them a year
can attest to that. And we'll attest to the fact that after 20 years, the
Corvette is more than going strong. It's still the epitome of the American
motoring experience."
Resonators were added to the dual exhaust
system on 1974 models which further helped quiet the
interior. The radiator and shroud were revised for better low-speed cooling.
The inside rear-view mirror width was increased from 8 inches (200 mm) to
10 inches (250 mm). For the first time, lap and shoulder seat belts were
integrated, but only in coupes. The FE7 Gymkhana "off-road"
suspension included stiffer springs and a stiffer front stabilizer bar with no
ordering restrictions. The new $7 FE7 suspension option was included with the
Z07 package — The $400 package (also included H.D. power brakes) was available
for L82 and LS4 cars with M21 transmission. 1974
was the end of an era for the Corvette with the last true dual exhaust systems,
the last without a catalytic converter and the last use of the
454 cu in (7.4 L) big block engine.
Hot Rod magazine in its March 1986 issue selected the
1973-74 Corvette LS6 454 as one of the "10 most collectable muscle
cars" in the company of the 1968-70 Chevelle, 1970 'Cuda, 1970 Challenger, 1966-67 Fairlane, 1968-70 AMX, 1970 Camaro
Z28, 1968-70 GTO, 1968-69 Charger, and 1967-68 Mustang. The big-block Corvettes were the only muscle
cars produced after 1970 worthy of the list.
1975–1977
The 1975 model was advertised as "a more efficient Corvette," as
service intervals were extended and electronic ignition and the
federally mandated catalytic converter were introduced with
"unleaded fuel only" warnings on the fuel gauge and filler door. Dual
exhaust pipes were routed to a single converter, then split again leading to
dual mufflers and tailpipes. Starting this year, tachometers were electronically driven. The Corvette began to be
influenced by the metric system as speedometers now displayed small subfaces
indicating kilometers-per-hour. 75's featured revised inner bumper systems with
molded front and rear simulated bumper guards. The urethane rear bumper, now in
its second year, reappeared as a one-piece seamless unit. This was the final
year for Astro Ventilation. Power bottomed out this year — the base engine
produced only 165 hp (123 kW) and the only remaining optional motor,
the L-82, dropped an astonishing 45 hp (34 kW), managing to deliver
205 hp (153 kW). With no larger engine available, L-82 hood emblems
began to appear on cars so equipped. Unchanged was the standard rear axle ratio
for the base engine, which remained at 3.08 with automatic and 3.36 with manual
transmission. This was the last convertiblefor the 1968-82
third-generation and only 12% of the cars were ordered as such. As in previous
years, a folding top came standard with roadsters and a body color or vinyl
covered hardtop was optional at additional cost. Anticipating further federal safety restrictions,
Chevrolet believed it would be Corvette's last soft-top model ever but the
convertible returned in 1986. Due to the state’s strict emissions standards,
this was the last year Chevrolet installed the L-82 engine in a Corvette
destined for California.
Car and Driver recorded a respectable 7.7 second 0-60 time in a
1975 base engine-automatic, making the Corvette still one of the fastest cars
available at the time. C&D said: "The Corvette feels highly competent with
power-everything to help you guide the long body around..."
1976 models featured steel floor panels shielding the catalytic converter
exhaust, weighed less than the previous fiberglass floor, and reduced interior
noise levels. Horsepower rose to 180 hp (134 kW) for the base L-48
engine; 210 hp (157 kW) for the optional L-82. To further reduce
cabin noise levels, cowl induction was dropped in favor of the air cleaner
ducted over the radiator, picking up outside air from the front of the car,
thus reducing wind turbulence at the base of the windshield. The hood was
carried over with its cowl vent grille and induction system non-functional. The
optional cast aluminum wheels were finally made available which reduced the
unsprung weight of the car by 32 pounds. Nearly 15% of the cars were
ordered with the new wheels at a cost of $299. A standard steel rim spare was
used. This was the last year for optional white striped tires as 86% of the
cars were being delivered with the optional white lettered tires. A new rear nameplate for
the rear bumper cover was introduced, eliminating the individual
"Corvette" letters used since 1968. An un-welcome change was the
"Vega GT" 4-spoke steering wheel, although its smaller diameter did provide
extra room and eased entry/exit. The steering wheel, color
keyed-to-the-interior, continued on 1977 thorough 1979 models limited to
non-tilt wheel cars only. GM's "Freedom" battery, a new sealed and
maintenance-free unit was now installed in all cars. The rear window defroster
option was changed from the forced air type of previous years to the new
"Electro-Clear" defogger, an in-glass heated element type. Even
without a convertible model, the Corvette still set new sales records.
Car and Driver recorded 6.8 second 0-60 times in both L-48 and
L-82 4-speed equipped 1976 Corvettes. The magazine ordered an L-48 4-speed for
a 4,000-mile (6,400 km) road trip to Alaska. C&D summarized: "The
Corvette was a big hit–we expected and thoroughly enjoyed that–but we were
surprised at how well it withstood the ordeal...once we recovered from the trip
we conceded that we'd developed new respect for a car we'd long regarded as
something of a put on. In every sense of the word, our Yukon Corvette proved to
be tough and we'd have to say that even the production versions
impressed us as coming closer to being real touring cars than we might ever
have thought. There's a lot more sincere ring now to our stock answer to the
question, Why a Corvette?"
1977 saw the steering column repositioned 2 inches (51 mm) closer to
the dashboard to allow a more "arms out" position for the driver. The
custom interior with leather seat trim was now standard, with cloth and leather
a no cost option. A redesigned center console permitted universal Delco radio
options. One consequence of this was an 8-track tape player was now an option.
Auxiliary gauges were restyled and the ammeter was replaced with a voltmeter. The sun visors were redesigned to swivel so as to
provide some glare protection from the side as well as the front. Chevrolet
responded to the criticism of the previous year’s steering wheel with an all
new three-spoke leather-wrapped unit, which was well received. Chevrolet
featured this new wheel prominently on the front of their new Corvette sales
brochure. The new wheel came on all cars fitted with the optional
tilt-telescopic steering column which was ordered on all but a few thousand
Corvettes. Corvette's refinement as a touring sports car continued as both power
steering and power brakes became standard and new options included body-colored
sport mirrors, cruise control, and a new convenience group. Cruise control was
only available on cars with automatic transmissions. The convenience group
included dome light delay, headlight warning buzzer, underhood light, low fuel
warning light, interior courtesy lights, and passenger side visor mirror. The
black exterior paint color returned (last offered in 1969). Unchanged was the
horsepower ratings for both base and L-82 engines. Early in production, the
engine paint color was changed from Chevy orange to Corporate blue. The
“Stingray” script, seen on front fenders since 1969 disappeared, but new cross-flags emblems
began appearing on fenders before the model year ended. Windshield posts were
now painted black for a “thin pillar” look and this was the final year of the
"sugar scoop" tunneled roof-line and vertical back window. A Corvette milestone was
reached during 1977 as Chevrolet had built a half million Corvettes since
production began in 1953.
1978 was the Corvette's twenty fifth anniversary,
and all 78's featured silver anniversary nose and fuel door emblems. A new fastback rear window was
the most dramatic and noticeable styling change, giving the ten-year-old C3
Corvette body style a fresh lease on
life. The fixed-glass fastback benefited both aerodynamics and increased the
usable luggage space behind the seats while improving rearward visibility in
the bargain. A shade was installed that could be pulled forward to cover the
rear compartment to protect cargo and carpet against the unrelenting sun. The
tachometer and speedometer were redesigned to match the new “aircraft styled”
center console and gauge cluster first seen the previous year. Redesigned
interior door panels were also new as well as an actual glove box was added in
front of the passenger seat, replacing the map pockets of previous years.
Available options now included power door locks, a power antenna, dual rear
speakers and a CB radio.The optional convenience group, introduced the previous
year, now included intermittent (delay) wipers, floor mats, and the passenger
side vanity mirror was an upgraded illuminated unit. The base L-48 engine
generated 185 hp (138 kW); Those destined for California or high
altitude areas produced 175 hp (130 kW). Gone was the chrome-plated
ignition shielding over the distributor, replaced with a metal-lined black
plastic unit. The single-snorkel air intake used since 1976 was changed to a
dual-snorkel set-up on L-82 equipped cars helping to boost that output to
220 hp (164 kW). L-82 engines were also now fitted with an aluminum
intake manifold which saved 24 pounds compared to the cast iron unit of
previous years. The Corvette converted to metric tires with the P225/70R15 as
standard. Wider P255/60R15 tires were available as an option and required
fender trimming from the factory for clearance. The fuel tank capacity
increased from 17 gal to 24 gal on all cars. To make room for the larger tank,
a smaller (P195/80D15) space saver spare tire was utilized.
Two special editions were offered to
celebrate Corvette's 25th year. Before he retired, Bill Mitchell had suggested
a Silver Anniversary model in his favorite color-silver, appropriately
enough-and it appeared as the $399 B2Z option package. The first two-tone paint
option offered since 1961, it presented silver over a gray lower body with a
separating pinstripe, plus aluminum wheels and dual "sport" outside
mirrors as mandatory options, which added another $380 to the cost. 6502
Indy-500 Pace car replica editions were produced featuring Black/silver two-tone
paint, front and rear spoilers, mirror-tint roof panels and contoured sport
seats. Reviewers praised the car's classic strengths including its impressive
straight-line numbers, especially an L48/automatic's 7.8 second 0-60 time
and top speed of 123 mph (198 km/h), and noted its more refined, less
rattling ride. On the other hand, they continued to note its weaknesses, like a
rear-end that tended to step out during sharp maneuvers and a cabin that was
still cramped and uncomfortable.
Road &
Track took a 1978 L82 to 60 mph (97 km/h) in
just 6.6 seconds, 127 mph (204 km/h) flat out, and covered the
quarter-mile in 15.3 seconds @ 95 mph.
1979 saw the crossed-flag emblems on
the nose and fuel door revert to the those seen on the '77 model. Three popular
features introduced on the '78 pace car replicas made it into this year’s
production; The new bucket seats, the front and rear spoiler package, and the
glass roof panels. The new lightweight “high back” seats were made standard
equipment. The new seats had better side bolster, provided easier access to the
rear storage area, and the seat pair resulted in a weight reduction of about
24 pounds. The bolt-on front and rear spoilers were offered as an option
and nearly 7,000 cars were ordered so equipped. Functionally, the spoilers
decreased drag by about 15% and increased fuel economy by about a half-mile per
gallon. A bigger hit were the glass mirror-tint roof panels, now a regular option,
with nearly 15,000 cars so fitted despite their costing $365. All T-tops were
now wired into the standard anti-theft alarm system. Tungsten-halogen high-beam
headlights became standard as did an AM-FM radio, and for the first time a
cassette tape player could be added as a $234 option. Heavy duty shock absorbers could now be ordered
without the full Gymkhana suspension. An auxiliary electric engine cooling fan
was first installed, but only on L-82 equipped cars with air conditioning. Rocker panels and rear window trim were painted
black. Output for all engines increased due to new
"open flow" mufflers. The dual-snorkel air intake introduced on L-82
cars the previous year was now fitted to all cars and the base engine now
generated 195 hp (145 kW). The optional L-82 engine increased to
225 hp (168 kW). The M21 close ratio 4-speed transmission continued
as an option at no cost but, as in previous years, could only be mated to L-82
engines. The wide ratio 4-speed continued to be available for all cars.
Noteworthy is that about 82% of the cars were ordered with manual transmissions
in 1968. In '79, less than 20% of the cars were delivered with manual gearboxes. This year reached an all-time high in Corvette
popularity. Production hit its peak in 1979 at 53,807, a record that stands to
this day.
1980–1982
In 1980, both front and rear bumper covers were
restyled with integrated aerodynamic spoilers
that resulted in a significant reduction in drag and increased radiator air
flow. The hood was also restyled. The crossed-flag emblems disappeared from the
front fenders and were revised to a more elongated style on the nose and fuel
door. L-82 emblems moved from the hood to the front fenders on cars ordered
with the optional high performance engine. This was the finale for the L-82,
now producing 230 hp (172 kW) but it could not be mated to a 4-speed,
as the manual gearbox was offered only with the base engine. The speedometer in
all cars read to a maximum of 85 mph (137 km/h), mandated by a new
and controversial federal law. Air conditioning became standard, as did the
tilt-telescopic steering column, power windows, exterior sport mirrors, and the
convenience group. New was an optional roof panel carrier that would mount to
the rear fastback deck. Many weight-saving components were introduced including
thinner body panels and an aluminum Dana 44 IRS (Independent Rear Suspension)
differential and crossmember. The new lighter unit replaced the arguably
stronger cast iron GM 10 bolt IRS differential. In line with further weight savings, the
aluminum intake manifold associated with L-82 engines since 1978 was now
installed in all cars. For the first time, due to California emission
considerations, a unique engine application was installed in cars delivered to
that state and was mandatory. This motor was a 305 cu in (5.0 L) V8 engine rated at
180 hp (134 kW), fitted with new tubular stainless steel exhaust
manifolds, and mated to an automatic transmission, also mandatory. The
carburetor and ignition timing were controlled by Chevrolet’s new Computer
Command Control system. The smaller displacement engine was not available in
any other state. California buyers were credited $50 as consolation but had to
pay for the California emissions certification which was $250. For comparison,
the L-48 350 cu in (5.7 L) engine, standard in the other 49
states, was rated at 190 hp (142 kW). The base price increased four
times during the model year raising the cost of the car by more than $1,200 to
$14,345,24.
In 1981, there was only one powerplant
available, a 350 cu in (5.7 L) engine that, like the L-48 base
engine the previous year, produced 190 hp (142 kW), but was now
designated the L81. The motor was certified in all states and available with
manual or automatic transmissions. Chrome air cleaner lids and cast magnesium
valve covers dressed up all engines. The stainless steel exhaust manifolds and
computer control system introduced on the 305 cu in (5.0 L)
California engines the previous year were now standard, as was an auxiliary
electric engine cooling fan. This, the last C3 available with a manual
transmission, so equipped, had a published 0-60 mph in 8.1 seconds.
This model year was the first to use a plastic rear spring, now a Corvette
trademark. The spring saved thirty-six pounds, but was limited to base
suspensions with automatic transmission. When equipped with Delco's new
optional ETR (Electronically Tuned Receiver) radio with digital clock, the
quartz analog instrument panel clock was replaced with an oil temperature
gauge. The cast aluminum wheels, optional since ’76, were now ordered on 90
percent of the cars at a cost of $428. New options included a power adjustable driver’s
seat and power remote outside mirrors. In mid-1981 production shifted from St. Louis, Missouri to Bowling Green,
Kentucky, and several two-tone paint options were offered.
1982 saw the debut of the
“Cross-Fire Injection” fuel delivery system. This TBI (Throttle Body Fuel
Injection) was not the type of fuel
injection installed previously in
some C1 and C2 Corvettes. It utilized two throttle bodies combined with
Chevrolet’s computer control system. The engine produced 200 hp
(149 kW) and was mated to a new four-speed automatic transmission with
torque converters bypass in the top three gears. Compared to the previous Turbo-Hydramatic 3-speed, the new 700-R4 transmission
had a lower first and second gear for improved low-end acceleration, and a
fourth gear overdrive that would reduce engine RPM by 30
percent at highway cruising speeds, resulting in better fuel economy. On the
downside, the new transmission was not considered a strong unit and proved
problematic. The final
model C3 Corvette's published performance numbers were 0-60 in
7.9 seconds-the quarter-mile in 16.1 @ 85 mph (137 km/h). This
was the last year for 8-track tape availability and new “cross-fire injection”
emblems appeared on front fenders. Nose and fuel door crossed-flags emblems
changed to a more squared design. Chevrolet knew this would be the last year of
an entire generation of Corvettes and so commemorated the occasion by offering
a Collector Edition with separate serial number sequencing, silver-beige paint,
unique wheels patterned after the 1967 model's bolt-on alloys, and an operable
rear hatch window.
Special models
ZL1 (1969)
For the 1969 model year the ZL1 option was offered
featuring an all-aluminum 427 cu in (7.0 L) big-block engine listed at
430 hp (321 kW) gross, it propelled the ZL1 through the 1/4 mile
in 12.1 seconds. The option cost $4,700 (the ZL1 was a $3,010 option that
consisted of aluminum cylinder block and heads on top of the $1,032.15 L88 option).
Though generally believed to deliver at least 100-hp (75 kW) more, this
has been proved as only rumors, proper testing of the engine reveled closer to
460 hp (343 kW) gross and net rating of only 376 hp
(280 kW).
According to Motor Trend in a late 1968 road test, the Corvette ZL1 was the
fastest production car ever produced (up to that time). For decades, automotive
experts believed only two were built (yellow and white coupes), however Car and Driver in December 1969, revealed a third red ZL1. It
disappeared after that 1969 road test and has never been found.
ZR1 & ZR2 (1970–1972)
The ZR1 special engine package was a $1,221.00 option
available exclusively with the LT-1 engine option. It included the solid-lifter
small-block engine, heavy-duty four-speed transmission, power brakes, aluminum
radiator, and a revised suspension with special springs, shocks, stabilizer
bar, and spindle-strut shafts. Since it was competition equipment, the ZR1
could not be ordered with power windows, power steering, air conditioning, a
rear-window defogger, wheel covers, or a radio. Only 53 1970-1972 ZR1's were built.
The ZR2 special engine
package was a $1,747.00 (1 year only) option originally planned for 1970, but officially released in 1971. It included the
special equipment in the ZR1 package, but for the 454 LS-6 engine. Per GM
policy, 1971 Corvette engines were detuned to run on low-lead fuel, except for the LS-6 V8, which was rated at 425 bhp
(317 kW) on premium fuel. 188 cars in the 1971 model included the LS-6
engine, with only 12 with the ZR-2 package. Some believe the "ZR" lettering to stand
for "Zora Racer", named after chief Corvette engineer Zora Duntov,
but in 2008, Corvette Production Manager Harlan Charles said, "the reality
is the codes are usually random and get meaning from enthusiasts."
Indy 500 pace car (1978)
The Corvette C3 was chosen as the pace car for the 1978 Indianapolis 500. Initially, 2500 Indy 500 replica pacers—100 for
each year of production—were scheduled for sale. But it was decided that each
of Chevrolet's 6200 dealers should have one for showroom display. Thus what was
called the Limited Edition Indy Pace Car Replica Corvette made up some 15 percent of total
production. Like the Silver Anniversary model, the Pace Car Replica was
actually an option package-RPO Z78. Its main distinction was black over silver
metallic with a bright red pinstripe in between with a spoiler added to each end
to alter appearance more dramatically. Pace car interiors reflected Bill
Mitchell's influence, with full silver leather or silver leather/gray cloth
upholstery and gray carpeting. All replicas were equipped with new thin-shell
design-lumbar support seats, new glass t-tops, alloy wheels, power windows, air
conditioning, tilt/telescope steering wheel, power locks, rear defogger, sport
mirrors, heavy-duty battery, and AM/FM stereo with either eight-track tape
player or CB radio. The final touch was the Indy 500 decal set included
uninstalled with each limited-edition car.
Collector Edition (1982)
The 1982 Collector Edition was
the first Corvette with a hatchback rear window, foreshadowing the C4
Corvette. A special color scheme was used inside and out and Collector Edition
badges were featured. The special, exclusive aluminum wheels were designed to
look like the optional bolt-on wheels of the 1967 model. The Collector Edition
had a "0" in the sixth digit of the VIN rather than the "8"
found on standard Corvettes. This was the first Corvette to sell for more than
$20,000, with a base price of $22,537.59. The Collector Edition had unlimited
availability and 6,759 were produced out of a 1982 total production of 25,407.
Engines
305 in³ "Calif. Only" LG4 V8 1980 180 hp (134 kW) net
327 in³ Small-Block V8 1968 300
hp (224 kW)
1968 350
hp (261 kW)
350 in³ Small-Block V8 1969 300
hp (224 kW)
1969–1970 350 hp (261 kW)
1970 370 hp
(276 kW)
1971 270 hp
(201 kW)
1971 330 hp
(246 kW)
1972 200 hp
(149 kW) net
1973 190 hp
(142 kW) net
1973–1974 250 hp (186 kW) net
1974 195 hp
(145 kW) net
1975 165 hp
(123 kW) net
1975 205 hp
(153 kW) net
1976–1977 180 hp (134 kW) net
1976–1977 210 hp (157 kW) net
1978 185 hp
(138 kW) net
1978 220 hp
(164 kW) net
1979 195 hp
(145 kW) net
1979 225 hp
(168 kW) net
1980–1981 190 hp (142 kW) net
1980 230 hp
(172 kW) net
1982 200 hp
(149 kW)
427 in³ Big-Block V8 1968–1969 390 hp (291 kW)
427 in³ Big-Block Tri-Power V8 1968–1969 400
hp (298 kW)
1968–1969 435 hp (324 kW)
427 in³ ZL1 aluminum V8 1969 430 hp
(321 kW) gross, 376 hp (280 kW) net[46]
454 in³ Big-Block V8 1970 390 hp (291 kW)
1971 365 hp (272 kW) G., 285 hp (213 kW) N.
1971 425 hp (317 kW)
1972, 1974 270 hp (201 kW) net
1973 275 hp (205 kW) net
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