1975 Chevrolet Corvette L48 Convertible: Only 165 HP And Just 61 Miles On This Final-Year C3 Convertible

Let’s say you had the opportunity to buy a bright red vintage Corvette convertible — one of the very last of the C3 generation — with close to zero miles, practically untouched. However, it was a 1975 car with the least-powerful engine Chevrolet had offered in the Corvette since 1956, the 165 hp L48. Still interested? Read on …

Although the 1963–1967 C2 Corvette had introduced the stylish Sting Ray coupe, Corvette buyers still preferred the convertible by a margin of almost 2 to 1 up through 1968, the first year of the C3 generation. The balance then swung sharply in the opposite direction in 1969, and Corvette convertible sales dropped sharply. From 1970 on, they were consistently under 8,000 units a year, and they dipped below 5,000 units in 1973.

With open cars under imminent regulatory threat in the U.S., Chevrolet decided that 1975 would be the end of the line for the Corvette convertible as well as the bigger Caprice Classic convertible. Production of both models ended in July 1975. The door jamb sticker in the red Corvette pictured here shows a build date of 7/75, so while this wasn’t THE last convertible off the line, it was pretty close. Corvette convertible production for 1975 totaled only 4,629 cars, the lowest since 1956. (The convertible would be back in the C4 line in 1986, but no one anticipated that in 1975.)

Despite the decline of the ragtop, total 1975 Corvette production was a robust 38,645, one of the Corvette’s best years to date and very close to 1969’s record. In fact, the Corvette was selling so well that the assembly plant in St. Louis was the only GM factory to work any overtime in 1975, and shifts were often scheduled for six days a week. The Corvette convertible was dead, long live the Corvette.

1975 was also notable for another reason: a major loss of power. For the first time in a decade, a big block V-8 was no longer available in the Corvette; the oil embargo during the 1974 model year had cooled any remaining demand for the LS4 Turbo-Jet 454 engine, so Chevrolet pulled the plug on the big engine before the 1975 model year began. The two remaining choices, the 350-cid L48 and L82, had each lost an embarrassing amount of horsepower for 1975. The optional L82 was down from 250 to 205 net horsepower, while the base L48 engine had fallen from 195 horsepower to … would you believe 165 hp?

The culprit was the more restrictive exhaust system that went with the adoption of a catalytic converter for emissions control. Catalysts were expensive, and even on the Corvette, Chevrolet was loath to shell out for more than one. So, instead of true dual exhausts, both the L48 and L82 now had both exhaust manifolds dumping into a single pipe ahead of the cat …

… and then branching out into separate mufflers behind it. The GM pelleted catalyst was fairly restrictive in itself, but the back pressure with this layout would have been hopeless in any case.

The available L82 engine, a $330 option, still had a much hotter camshaft and an extra half-point of compression to keep it on the high side of 200 hp. However, Chevrolet hadn’t been able to complete its emissions certification until after the start of the model year, so the L82 was rare this year. All but 2,372 1975 Corvettes had the standard L48.

You’re probably wondering, “How slow WAS a 165 hp Corvette?” If you believe Car and Driver, it wasn’t THAT bad: They tested a 1975 L48 coupe with Turbo Hydra-Matic, a 2.73 axle, and air conditioning — close to the worst-case scenario for Corvette performance in 1975 — and got 0 to 60 mph in 7.7 seconds, the quarter mile in 16.1 seconds at 87.4 mph, and an observed top speed of 129 mph. For a U.S.-market 1975 car, that was respectable enough, if hardly thrilling compared to earlier big block ‘Vettes. However, Road & Track‘s 1976 80 lb lighter L82 test car couldn’t match those figures even with the more powerful L82 engine, close-ratio 4-speed, and 3.55 axle, so take that as you will.

The point is that a base-engine Corvette was a 3,700 lb car with a mildly tuned engine that was now, in effect, trying to exhale through a straw. Compared to a 350 Impala, the Corvette was still a rocket, but you needed to be very cautious about stoplight duels unless you first availed yourself of the vast cornucopia of aftermarket parts available for the 350. Which many buyers likely did: According to Chevrolet, typical Corvette customers in this era were young men (median age was 30) with plenty of money (median income was about $23,000). Quite a few fancied themselves serious drivers; almost 10 percent ordered the extra-stiff FE7 gymkhana suspension, which cost only $7 upfront, but added a jarring edge to the Corvette’s already stiff ride.

In specifications, the C3 was still in the first rank for chassis sophistication in 1975, with fully independent suspension, four-wheel disc brakes, and (somewhat belatedly) fat radial tires. This didn’t necessarily translate into first-rank handling. With the optional fast-ratio power steering and the standard suspension, which had no rear anti-roll bar, Car and Driver found the Corvette much too prone to oversteer, requiring great care to keep the tail in line in tight turns or hard stops. With the low recommended tire pressures, they recorded a meager 0.67 g on the skidpad, worse than a lot of cheaper four- and six cylinder coupes. (Road & Track‘s 1976 coupe, which had the FE7 gymkhana suspension and lighter aluminum wheels, managed a much more respectable 0.748 g.)

With a car like the Corvette, you could always just relax and let the styling speak for itself. The C3 was one of the most extroverted production models you could buy in America in the mid-’70s. It was already showing its age, but in an era when most new cars seemed to get blockier and boxier every year, it was hard to match the Corvette for sheer visual spectacle, especially in bright colors like this Mille Miglia Red. Contemporary buyers preferred white or silver (a Corvette was cop-bait enough in less conspicuous hues) but in red, the C3 remains eye-popping.

Car and Driver complained in 1975 that Chevrolet seemed “determined to sterilize all the character out of the command station” of the Corvette, a charge I still don’t really understand. True, the C3 interior did lack many things, like storage space, ventilation, ergonomics, and build quality. Even with the $154 Custom interior, which included leather upholstery and woodgrain trim, the cabin was not especially luxurious, and the closest it had to a glove box were some map pockets on the passenger side of the dash and a small lockable bin in the stowage area behind the seats. However, the Corvette interior certainly didn’t lack for character, and the giant 160 mph speedometer and 7,000 rpm tachometer made immediately clear what kind of car this was supposed to be.

Even if you never blipped the throttle in anger, the Corvette could almost justify its price on sex appeal alone. It was not inexpensive (the original sticker of this convertible was $7,855), but it was what our British cousins used to call a “crumpet-catcher” par excellence. If you didn’t look like Burt Reynolds or Farrah Fawcett in the mid-1970s, driving a new Corvette convertible was surely the next best thing.

This particular car had only 60 miles on the odometer when these photos were taken, and is about as close to showroom condition as a 50-year-old Corvette can be, short of vacuum-sealing the entire car. The Bring a Trailer listing is vague about its backstory, but my guess is that the car was ordered near the end of the 1975 model year, with the expectation that it would be a future collectible, and went immediately into long-term storage. (The listing says it was never titled.)

After selling in 2021 for $68,000 — about twice the current going rate for a nice 1975 convertible — I suspect the car went back into the cryogenic chamber. Surprisingly, it doesn’t appear to have been flipped since that sale, at least not at any of the major auction services. However, with an ultra-low-mileage original car like this, it makes no sense to drive it, since that would rapidly diminish its value. So, if it’s not on display, it’s probably in storage again.

That seems too bad, since part of the appeal of these later C3 Corvettes is that they aren’t so beloved or so valuable that people get tense about actually driving them, or modifying them to taste. No stock Corvette of the latter ’70s is an outstanding performer by most standards, but few people today choose collector cars based on 0 to 60 times or skidpad ratings, and if you’re concerned about that, the aftermarket offers many possibilities.

The big appeal of a car like this remains much the same as it was 50 years ago: A C3 Corvette offers more swaggering macho image than almost anything you can buy for less than six figures. In brightly colored convertible form, its power to turn heads is still undiminished, however many horses it has under the hood.

 

Related Reading

Curbside Classic: 1973 Chevrolet Corvette – A Car And An Author Come To Terms (by J P Cavanaugh)

Vintage R&T Road Test: 1973 Corvette – “Changes For 1973 Produce Mixed Results” (by Paul N)

Curbside Musings: 1974 Chevrolet Corvette Stingray Convertible – Don’t Say Goodnight Tonight (by Joseph Dennis)

Road & Track 1974 Vintage Review: Five Exotic Open Sports Cars – Corvette, Porsche 911, Dino 246GTS, Mercedes 450SL and Jaguar E-Type V12 (by Paul N)