America's sports car underwent big changes in 1968. The beloved Sting Ray body that had blown away everyone in 1963 was gone, replaced by an even more revolutionary design based on the fabulous Mako Shark show car. Seven inches longer and two inches lower than the '67 model, the new Corvette featured a Kamm-style rear with an integral ducktail spoiler.
Inside, the cockpit was also new, featuring slim-line bucket seats with high seatbacks and bigger bolsters for more support. The interior was dominated by the large center console, which was integrated into the dash and contained the HVAC controls as well as the shifter. The dash center stack contained a complete set of gauges, as well as the wiper controls and radio. Behind the three-spoke steering wheel was a downward-sweeping instrument panel containing twin pods: one on the left for the 160-mph speedometer, and another on the right for the 7,000-rpm tachometer. The traditional vent windows were gone, replaced by Astro Ventilation with air outlets on either side of the dash.
As on the '63-'67 Corvettes, the headlamps were concealed. Instead of being electrically actuated and rotating to open, however, the new lamps were operated by vacuum and "popped" open. The windshield wipers were concealed behind a movable cowl panel and were also operated by vacuum. (Unfortunately, both features would prove troublesome.)
Both a coupe and a convertible were offered. The coupe featured removable roof panels, which were attached to a "T" bar that connected the A and C pillars and provided additional rigidity. The rear window could also be removed.
Although this new body was swoopy and sexy, the '68 Corvette was not without its problems. For beginners, the new body style had actually been planned for a 1967 debut, but issues with the tall front fenders inspired by the Mako Shark delayed its release. Specifically, the fenders were too high and prevented the driver from seeing over them. They had to be lowered, a modification that cost Chevrolet a year in getting the new car to market. The result was a rush job that, when it finally hit dealers, was plagued with poor-fitting panels, serious quality-control issues, and chronic cooling problems, especially for the big-block-equipped models.
While the long, low nose of the '68 model was more aerodynamic than its predecessor, it wasn't as effective at providing the airflow needed to cool the engine, especially with the bumpers and headlamp assemblies in place. Chevrolet's styling department refused to compromise on the design, so it was up to the engineers to overcome the problem. The '68 was the first "bottom feeder" and was a learning experience when it came to developing effective underside cooling ducts.
This was also the year Zora Arkus-Duntov was named Corvette Chief Engineer. He had been away from the program, and the '68 model suffered from it. Now he was back and refocused on ensuring that the problems inherent to the car were corrected.
While the cockpit and body were new, the car's chassis, suspension, and brake engineering were relatively unchanged from 1967. The same was true of the powertrain selections, with one major exception: Automatic-transmission buyers could now select the M40 Turbo-Hydramatic three-speed that replaced the outdated two-speed Powerglide.
Engine choices were carried over from 1967 as well. Two 327ci engines were offered: The standard version was rated at 300 hp, with the 350hp L79 available as an option. Five big-block engines-all displacing 427 cubes-were also on the options menu. Selections started with the L36, a four-barrel, hydraulic-lifter engine pegged at 390 hp. Next up was the 400hp L68, also with hydraulic lifters but equipped with a trio of Holley 2300C two-barrel carbs. The L71, meanwhile, produced 435 hp, thanks to a hotter camshaft and mechanical valvetrain. It, too, was fed by three two-barrel Holleys.
If that hardware wasn't enough, the Corvette buyer had two more choices. The king of the hill was the L88, a purebred race engine for the street. Ridiculously underrated at 430 hp, the L88 had a cast-iron block and lightweight aluminum heads. With mechanical lifters, a whompin' 12.5:1 compression ratio, an aluminum intake, and a massive Holley 4150 four-barrel, the L88's real output is estimated to have been in the 560hp range. Tellingly, creature comforts such as radios and heaters weren't offered when the L88 option was checked off.
The final big-block engine was the L89. The L89 option combined the cylinder heads on the L88 with the L71 engine and its 3x2 induction setup. Even in showroom-stock condition, an L89 Corvette was easily capable of mid-13-second quarter-mile times at speeds in excess of 107 mph.
Only 624 L89s were produced. The Tuxedo Black convertible shown here is owned by Rick Treworgy of Punta Gorda, Florida, and boasts the L89 engine mated to an M21 close-ratio Muncie four-speed and 3.55:1 Posi-traction rear. Rick purchased the car 10 years ago at the NCRS Winter Regional Meet in Florida. "Besides some small tweaking here and there," Rick told us, "it has always looked and driven flawlessly."