GM's first "SS"... [PIC]

By the mid-fifties, chief engineer Zora Arkus-Dontov was convinced that Corvette sales would increase if the car could be successfully raced at prestigious international events. By 1956 he had placed a handful of modified Corvettes ( known as the SRs) in Sebring and Daytona  but realized to successfully compete he would need GM's first dedicated race car. Mitchell gave his team a D-Type Jaguar to work with, but nothing really panned out. They were then presented with a Mercedes 300SL and, with the body removed, they went to work modifying the chassis to accommodate a production 283 cid V8 equipped with Rochester Ramjet fuel injection with solid lifters and a special "Dontov" profile cam producing 310hp. Rather than Fiberglas, the body was made of magnesium. Brakes were modified Chrysler... outboard in the front and inboard in the rear. The car had quilted insulation in the cockpit because unlike the Fiberglas on the mule car, the magnesium body conducted the engine heat throughout. This project was named XP-64 and then received its official name of the Corvette SS (for Super Sport).

The work was completed just before the '57 Sebring and Duntov had signed Juan Manuel Fangio and Carroll Shelby to do the driving, but they both opted out. John Fitch and Piero Taruffi drove in the race. The car was retired after 23 laps due to a series of bugs and errors that could have been solved if there was more time for testing. The target of entering LeMans became impossible due to the Automobile Manufactures Association enacting a ban on racing by its members. Later, the FIA limited entrants to 3.0 liters. Its swan song came in 1959 when Duntov took the car on the Sebring track and took the fastest lap of 155mph.