The Chevrolet Corvette C3 was produced from 1967 to 1982 and is the third generation of the Corvette sports car. C3 Corvettes featured a new body and interior, but the chassis and engines were carried forward from the previous generation C2.
The Early Years
Classic and Sports Car explains that the design of the C3 Corvette resembled the second-run Mako Shark II concept car that was initiated in 1964. As with the C2, the 1968 C3 Corvettes were offered as a coupe or convertible. The coupe featured removable T-top roof panels and rear window. Convertible models came with a folding soft top but, for an extra cost, a hard top was available.
For 1969, the displacement of the small block engine was increased from 327 to 350 cubic inches (5.4 to 5.7-liter) although the power was unchanged. Other drivetrain options stayed the same. The width of the steel wheels was increased to 8 inches and white lettered tires were offered as an option for the first time, while the red-striped tires were discontinued.
Seven rear axle ratios were available, that ranged from 2.73 to 4.56. A Positraction rear axle was an option, but over 95 percent of C3 Corvettes had it installed. The Sting Ray name from the C2 was revived on C3 Corvettes in 1969, although it was now Stingray as a single word, per Autolist.
Changes to the exterior included:
- Redesigned door handles
- The introduction of headlamp washers,
- A new black grille,
- Integrated backup lights.
The interior changes were:
- Redesigned door panels
- Standard headrests
- The ignition switch was relocated to the steering column
- The diameter of the steering wheel was reduced to allow easier entry.
This was the sole year that a ZL1 option was offered with its big block 430 horsepower 427 cubic inch (7.0-liter) aluminum engine.
Growing Up
Per Bullet Motor Sports, in 1970, an eggcrate grille was introduced with matching fender vents, and the tailpipes were increased in size and changed from circular to rectangular. The seats were redesigned and an upgraded interior option was offered with leather upholstery, wood-grained accents, and upgraded carpets. Standard features now included a wide-ratio four-speed manual transmission, the Positraction rear axle, and tinted windows.
Newly offered was an LT-1 engine, a 350 cubic inch (5.7-liter) 370-hp V-8. Models with this engine featured a hood bulge and unique decals, but they weren't available with air conditioning. An LT-1 was timed at 14.4 seconds for the quarter-mile at a speed of 101.7 mph for which it was compared to a Porsche but without the same expensive price tag.
The 1971 model year saw the C3 Corvette engines being down-tuned with decreased compression ratios to make them compatible with lower octane gasoline. Available in this year was an LS6 454 cubic inch (7.4-liter) 425-hp big-block engine that could be paired with an automatic transmission. It was the highest output engine of this period.
Introduced for 1972, the SAE net horsepower standard replaced the old SAE gross measurement system resulting in lower engine output figures. The LS5 big block 454 cubic inch (7.4-liter) engine was now rated at 270 horsepower. This engine was not available in California because of the state's stricter emission standards than was required by federal laws.
Major Changes
It was in 1973 that the Corvette began its transition from a muscle car into a sports tourer with an improved ride and a 40 percent reduction in interior noise. While the chrome rear bumper was retained, the front end now sported a lightweight energy absorbing urethane bumper to comply with federal five mph impact requirements. The high-performance LT-1 engine option was replaced by the L-82 with an output of 250 horsepower. Almost 20 percent of the production was ordered with this engine.
A new rear end design was introduced in 1974 with a urethane cover featuring recesses for the lights and an integral holder for the license plate. The rear bumper would now also pass federal impact tests. The changes brought the C3 Corvette's design right up-to-date from its ‘60s origins and met with the approval of most enthusiasts. Car and Driver magazine said, '...We think the front and rear together produce a 'molded' shape that speaks of function rather than decor.'
The Transitional Years
To comply with federal regulations, a catalytic converter was introduced in 1975 so that only unleaded fuel could be used. This, along with newly extended service intervals and electronic ignition, made C3 Corvettes more efficient. An electronically controlled tachometer also became standard in this year and the speedometer featured a subdial showing kilometers per hour. The former two-piece rear bumper was replaced by a seamless one-piece bumper.
Weight savings were made in 1976 with the fiberglass floor panels being replaced with steel panels that also reduced sound levels in the co*ckpit. Cast aluminum wheels were offered as an option. White lettered tires were now being fitted to 86 percent of C3 Corvettes. In 1977 the steering wheel was moved closer to the dashboard to provide a better driving position, leather upholstery became standard, and the center console and auxiliary gauges were redesigned.
Rising Again
For the Corvette's 25th anniversary in 1978, the vertical rear window was replaced with a fastback design that improved the aerodynamics and looks of the car, while also increasing the luggage space. The instrument cluster was redesigned to complement the center console and a glove compartment replaced the map pocket in front of the passenger.
Introduced for 1979 were new high back bucket seats that provided more side support. The 1978 pace car replicas featured glass roof panels and a front and rear spoiler package that were optional on other models. Almost 7000 Vettes were fitted with the spoiler that reduced drag and improved fuel economy. The mirror-tint glass tops featured on around 15,000 cars. For '79 a cassette player was offered as an option.
The Final Chapter
Bullet Motor Sports explains that the early ‘80s saw the introduction of standard power windows, air conditioning, and a tilting and telescoping steering column. In the last model year for C3 Corvettes, the Cross-Fire Injection engine debuted that delivered 200 horsepower. It was paired with a new four-speed automatic transmission with overdrive in top gear that improved fuel economy at cruising speeds.
In this final year, a Collector Edition was offered by Chevrolet. It featured unique paintwork and wheels, an opening rear window, and separately sequenced serial numbers.
Information and research in this article verified by ASE-certified Master Technician Duane Sayaloune of YourMechanic.com. For any feedback or correction requests please contact us at research@caranddriver.com.
Sources used:
https://www.classicandsportscar.com/features/buyers-guide-chevrolet-corvette-c3
https://www.autolist.com/chevrolet-corvette/chevy-corvette-c3-generation
http://bulletmotorsports.com/history-c3-corvette/
https://www.caranddriver.com/
https://www.caranddriver.com/features/g22035705/fully-vetted-the-visual-history-of-the-chevrolet-corvette/
