The “malaise era” was not kind to America’s True Sports Car. Over the course of the 1970s, Chevrolet’s Corvette transitioned from no-nonsense sports machine to leather-lined grand tourer ... partly because of increasingly stringent emissions, economy and safety standards, and partly in an effort to keep up with the demands of the ever-wealthier people buying them.
The later years of the C3 generation get a bad rap from some corners of the Corvette fraternity, but they still have a lot of fans, and their mere existence shows that Chevy was determined to fight the good fight and keep their "halo" car on the road. Here’s a look at Corvettes through the ‘70s, from least interesting to most desirable.
This represents the low ebb for Corvette performance in the 70s, largely due to the introduction of the federally-mandated catalytic converter designed to help reduce dangerous pollutants from the exhaust. This increased exhaust backpressure and reduced power output. It also meant the end of a true dual exhaust for the ‘Vette, which sent two exhaust pipes from the engine into a single converter and back out to dual exit pipes.
The base 5.7-liter V8 engine in the ‘75 Corvette — known as the L48 — produced just 165 horsepower. That’s a mere seven horsepower more than the 2.0-liter four-cylinder mill in your average Honda Civic. The available L82 engine was good for just 205 hp, and the big-block was gone for good. At least you could still get a convertible.
This was the first year since the C1’s debut in 1953 that a convertible Corvette was not available. GM was convinced that proposed federal rollover safety standards would legislate ragtops out of existence. Those regulations never took effect, and it would take another 12 years before Chevrolet would again offer a Corvette convertible.
Fortunately, Chevy’s engineers found 15 more horsepower for the standard L48 V8, bringing it up to 180hp. Unfortunately, the division’s attempt to cut corners gave the ‘Vette the same standard four-spoke sport steering wheel as the Vega GT. This was not a great look for the most expensive Chevrolet.
All of the Corvette news for ’77 was in the cockpit. Chevrolet made the former “custom” interior standard, giving each ‘Vette leather or cloth-and-leather seats, wood grain trim on the doors, and higher-grade carpeting. It was an acknowledgment that the C3 had become as much a high-end touring coupe as a sports car.
1977 was also the first year of a re-designed center stack which allowed the Corvette to use standard Delco radios, as well as HVAC controls cribbed from the Chevette. In addition, the C3 adopted the corporate multi-function wand that moved wiper/washer controls from their odd location above the center dash vents to the turn signal stalk.
Even casual Corvette observers know that the sports car’s 25th anniversary heralded a major new look. Let’s start with that big fastback rear window, which smoothed airflow over the back of the car and increased the ‘Vette’s usable luggage capacity. It also gave Chevy an opportunity to increase the size of the C3’s gas tank from a healthy 17 gallons to a nearly-transcontinental 24 gallons.
And then there were the special editions: the silver-over-metallic gray “Silver Anniversary” package (a tribute to outgoing GM design chief Bill Mitchell), and the black-over-silver Pace Car edition, marking the first time in history that the Corvette paced the Indianapolis 500.
After the big changes to the C3 marking the Corvette’s 25th anniversary, the ’79’s differences were more subtle. Under the hood, the standard L48 V8 pumped out ten more horsepower, for a total of 195. On the inside, the high-back buckets from the ‘78 Pace Car became standard, in the buyers’ choice of leather or cloth-and-leather finish.
But 1979 was also the last year that Corvette buyers had to pay extra for air conditioning and power windows. And it would be another three years before owners would be able to open that fastback rear window. Owners didn’t seem to care, and Chevy sold more than 53,000 Corvettes in the decade’s last year.
When the federal government introduced its five-mph rear impact standard for the 1974 model year, Americans saw a lot of cars with clunky battering-ram-style bumpers. So Chevrolet’s design team deserves a lot of credit for finding a way to give the Corvette a fully legal rear bumper without having it look like an Impala ... or worse, an MGB.
That was a notable first for the C3, but ‘74 was also the last year for the giant 7.4-liter V8 engine that by the end was rated at 270 horsepower. In a prophetic note, the official Corvette brochure also makes a reference to the car having the grace and refinement of a personal luxury car. The long drift into the slow lane was proceeding.
The ’73 ‘Vette was moving into the future literally nose-first: the sleek new urethane front bumper introduced that year was designed to meet the government’s five-mph impact standard. In addition, a new hood for ’73 added functional cold-air induction. Under the car, Chevrolet made radial tires standard equipment and retuned the suspension for improved handling and a quieter ride.
But as Chevy gave-th, Chevy took-eth away: the hardtop’s glass rear window was no longer removable. The solid-lifter LT1 V8 was off the order sheet, leaving Corvette buyers with just three engines to choose. And in a further break from the ‘Vette’s competition past, Chevy stopped naming Corvette paint colors after well-known race courses, leaving just “Mille Miglia Red” and “Elkhart Green” in a sea of new 'Vette-specific hues.
It’s easy to think a Corvette from this era is pretty simple … big engine in front, big tires underneath, two seats inside … but the C3 had some interesting technology for the time, including headlamp washers and fiber-optic light monitors. Both of those features were eliminated for ’72 as GM slowly de-contented its marquee sports car.
Under the hood, the Corvette’s engines again appeared less powerful, even though that was an illusion brought on by the industry’s switch from reporting “gross” horsepower output to “net” horsepower (meaning as installed in the car). So the ‘Vette’s standard 5.7-liter V8 suddenly went from 270 horsepower to 200, despite being the same engine.
Let’s remember what was happening in the 70s. Government regulators banned the use of lead as an octane booster in motor fuels, because of a link to cognitive difficulties in children. Auto companies were years away from sophisticated computer engine control, so their response to lower-octane fuels was to reduce compression ratios. This made cars drivable without knocking, but it also took a toll on output.This started to show up on Corvette order forms in ’71, as the base V8 dropped from 300 to 270 horsepower. Optional engines also saw drops in output in what was otherwise a carry-over year for the ‘Vette.
This represents the very best of Corvette in the 70s. On the outside, Chevy’s stylists added larger front turn indicators and rear exhaust cutouts to the C3 introduced two years earlier, as well as egg-crate side vents to match the new grille. They also gave the wheel wells a deeper flare, to help deflect stones and debris churned up by the big F70 x 15 tires.
Inside, Corvette buyers could select leather upholstery as part of a “custom” trim package. Engine choices included the solid-lifter LT1 5.7-liter V8 (unavailable with air conditioning or automatic transmission) and the LS5 7.4-liter V8, good for a reported 390 horsepower. Indeed, checking the correct boxes on the ‘Vette’s order form could bring the buyer a track-ready race car, courtesy of their local Chevrolet dealer.