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Celebrating 50 years of Chevy’s third-generation Corvette

Published in blog.hemmings.com

All images courtesy of General Motors

Now produced for more than 65 years, Chevrolet’s Corvette has not only firmly cemented its place as “America’s sports car,” it has also earned enough of a legacy to have plenty of milestone anniversaries to celebrate. And this year is no different, with the third-generation ‘Vette celebrating its golden jubilee in 2018.

Heavily based on the Bill Mitchell-designed Mako Shark II (just as the previous-gen was based on the Larry Shinoda-penned Mako Shark I), the ’68 Corvette kept the previous model’s overall proportions—and literally its chassis underneath—while introducing an entirely new design that was as fresh as it was polarizing to some ‘Vette enthusiasts. Despite what collectors may think today, the third-gen Corvette proved an enormous hit.

The names Stingray and Sting Ray had been around for a while, first with a late 1950s concept/racer and later with the 1963 to 1967 production models that carried the Sting Ray name. But the introduction of the 1968 Corvette truly embraced the ray motif with its upswept fenders at all four corners of the car. Technically not a shark, but closely related genetically, the sting ray may have inspired the 68’s design motif, but fans quickly dubbed it the “shark” Corvette, a nickname which sticks to today. Though it debuted in ’68 with chrome bumpers at both ends and had its swan song in 1982 with no more shiny bits on the ends of the car, no one wonders which design you are talking about when you say “Seventies Corvette.” Credit for the design has been assigned to Mitchell, Shinoda, and David Holls.

As for the name, the ’68 Corvette carried no “Sting Ray” badges on its body, though the sales literature of the day included it. For 1969, “Sting Ray” became “Stingray” and it appeared as one word on the front fenders, right above the gill-like vents behind the front wheels.

On the auto show circuit shown here, the 1968 Corvette was paired with an original 1953 Corvette.

With the second-generation models barely in production in the mid-1960s, Chevrolet had multiple engineering and design teams competing to design a Corvette with the engine behind the driver, either in a mid-engined layout like the Ford GT40 and Lamborghini Miura or in a rear-engined format like the Porsche 911 or Chevrolet’s own Corvair. Though fullsize prototypes of these two layouts were developed, GM had not developed a transaxle robust enough to handle the thunderous power of its high-performance V-8s, in either big or small-block varieties. Cost wise, developing an all-new chassis for such a layout would also have been prohibitive, pushing the Corvette into Porsche and higher-priced brackets—a market that would have made the red, white, and blue, all-American Corvette a tough sell against more sophisticated European competition.

Such an exotic Corvette might not have worked out, but with the relatively sophisticated second-generation Corvette’s chassis already a proven race winner, Zora Arkus-Duntov, the legendary leader of the Corvette engineering team, ultimately set his people to tweaking the existing machine to accommodate the new design. With its fully independent suspension and four-wheel disc brakes, along with some of the most robust and powerful drivetrains on the market, going with the existing proven chassis wasn’t exactly the worst compromise.

As with the second-generation ‘Vette, both a convertible and a fixed-roof coupe were planned for the third-gen car, but designers had a little something up their sleeves for enthusiasts who wanted the solidity of a coupe but the feeling of open-air motoring. Initially experimenting with a removable center section of the roof, along with a removable rear back window, the designers and engineers compromised on what became the first T-tops available on a production vehicle as the Vette needed that longitudinal bar separating the individual roof sections for body stiffness. It ended up being a feature that buyers loved.

Third-gen Corvette details are shown in this press handout from 1968.

Underneath, the ’68 Corvette featured much the same mechanicals that had made the previous version a winner on the street and on the track. With a selection of big-block and small-block V-8s for power, the Corvette options menu in 1968 would have looked familiar to anyone who had shopped for a ’67. The standard small-block V-8 came in the form of a single four-barrel-equipped 327-cu.in. engine with 10:1 compression ratio that was good for 300 horsepower at 5,000 rpm. Optional was the L-79 version of the 327 that featured an 11:1 compression ratio, a Holley four-barrel and a high-performance camshaft that boosted output to an impressive 350 hp at 5,800 rpm. Torque remained the same 360 lb-ft for both engines.

As the muscle-car era was still reaching its peak, Chevrolet also officially offered a trio of 427-cu.in. big-block engines to Corvette buyers in 1968. The “base” L-36 427 (if such an engine could ever be considered a base model) produce 390 horsepower at 5,400 rpm via 10.25:1 compression and a big four-barrel carburetor. A pair of tri-power engines also were on the menu, including the 400-hp L-68 (also fit with 10.25:1 pistons) and the 435-hp, 11:1, solid-lifter L-71, equipped with higher-flowing heads and an even more aggressive camshaft, which resulted it a fairly high 5,800-rpm power peak.

But beyond the menu were two special-order engine options that have become legendary today. The L-89 featured all of the L-71’s go-fast bits plus aluminum cylinder heads in lieu of the L-71’s cast-iron units. Though not rated any higher than the L-71’s 435-hp output, the L-89 did offer about 75 pounds of weight savings over L-71-equipped Corvettes. But the most outrageous engine option was the L-88. Essentially a race-only engine, the L-88 featured high-performance aluminum heads, a race-level cam grind and 12.5:1 pistons that required the use of 103-octane race fuel. Though a somewhat overused expression, Chevrolet did vastly underrate the L-88’s output, listing it as producing 430 horsepower—five less than the L-71/L-89—in order to discourage the man on the street from buying one. The division had to offer it to customers in order to homologate the engine for sports car racing.

Chevrolet produced just 624 L-89-equipped Corvettes and 80 L-88 Vettes in 1968, miniscule numbers in comparison to the division’s overall output measure in the millions. Today, collectors recognize that rarity with L-89s going for big money and L-88s going for, well, insane money.

With the second-gen Corvette so well loved by the press and its fans, and with the Mako Shark II having been on the show circuit for a few years, tied together with the third-gen’s introduction in 1968 instead of its original plan as a ’67 model year car, the car wasn’t exactly well received. One magazine criticized it for its “derivative” styling while another called it out for being “wretchedly excessive and bloated.” Designers, intent on styling the car to make it stand out, ultimately made a car that was bigger outside, but smaller inside and seemingly with driver and passenger accommodation and comfort as an afterthought. Overheating, too, was an issue with the sleek body.

Of course, we all know what weight the critics carry into the showroom, right? Despite those naysayers, Corvette sales jumped to new heights in 1968 and, save for the strike-addled 1970 model year, those sales numbers pretty much continued to climb for nearly the entire 15-year production run of the third-gen Corvette.

Say what you will about the so-called “malaise era” of cars during the 1970s and into the early 1980s, but the third-gen Corvette was a big seller, no matter how you slice it. Corvette’s best years were during the third generation, with average sales higher than any other model and the peak coming in 1979. With no convertible option (that went away in 1975) and peak power of 225 hp from the four-barrel L-82 350-cu.in. V-8., Corvette still found its way into plenty of enthusiast’s garages as Chevrolet dealers moved an astounding 53,807 of them in 1979. Amazingly, Corvette C3’s best years were from 1976 through 1981, with an average of more than 46,000 per year and never less than 40,000, even though the design was thoroughly aged by then.

In another promotional photo (with a Cadillac in the background, no less), a big-block Corvette is shown with its raised hood and “427” callout on the bulge. 

Corvette’s designers and engineers regularly updated the car. With the obvious changes in the car’s powerplants, owing to changing consumer tastes and ever-more-difficult-to-meet emissions regulations, the last big-block Corvette, the 454-powered models, ceased production after the 1974 model year, when the big-block was rated at a still respectable 270 hp (SAE net). Just the year before, in 1973, the chrome front bumper gave way to a urethane nose with integral bumpers, designed to meet the 5 mph federal bumper-bashing requirement. The two-piece rear chromed bumpers were gone by 1974, too.

As the third-gen Corvette’s overall performance dropped with engine horsepower, designers focused on making the car quieter and better riding, along with design updates that kept pace with the times, yet still clearly said “Corvette.” Clearly, there was no mistaking a Corvette in a world of Novas, Volares, and Mavericks.

But Chevrolet hadn’t given up on performance by any measure, even as it fought the good fight against both federal and even more-restrictive California emissions regulations in finding any lost horsepower. Speed came by way of handling improvements in the form of a couple of option packages. The FE7 “gymkhana” option, introduced in 1974, offered stiffer shocks and a fatter anti-roll bar. The Z07 “off-road suspension” included heavy-duty brakes. The Positraction limited-slip differential was optional some years and standard other years. Likewise, buyers (in most states, most years; sorry, California in the late Seventies) could opt for a four-speed or close-ratio four-speed manual as well as a three-speed TurboHydramatic automatic transmission. (Chevrolet only ever offered the second-gen cars with a two-speed Powerglide option for an automatic.)

Over the years, the body changed as well, with the convertible being dropped after 1975 and the notchback look with the vertical rear glass going the way of the dodo for 1978, when a fastback roofline with a large, curved rear backlight became the only available body style. The 1978 model year saw two special editions that collectors craved when new: a two-tone silver on gray 25th anniversary model and a two-tone black-over-silver Indy pace car replica. Look around and you will still find many low-mile examples of these specials.

Corvette collectors tend to favor the early first and second-gen cars, while Corvette drivers tend to prefer the later, more-refined cars from the most recent generations. But in between there exists a fair number of affordable, fun, distinctively styled cars. Since Corvettes are rarely thrown away, though the frames below the plastic bodywork do suffer from rust if not cared for, there are plenty to choose from.

The second-gen Corvette was a tough act to follow and though the critics took a while to warm up to it, the third-gen Corvette ultimately proved a worthy and long-lived successor. Today, with some 65 years of production behind it and surely many more anniversaries to follow, celebrating the 50th anniversary of the introduction of the most-popular Corvette ever seems a fitting tribute.