The XP-755 was designed and the prototype was built in the beginning of 1961. Bill Mitchell was very excited about the double-bubble roof, the side exhausts and rear. It is equipped with a single four-barrel carburetor that produces upwards of 425 horsepower. The Corvette XP-755 Concept had a streamlined design, pointed snout and outlandishly future looking elements everywhere. The 1961 Mako Shark I (XP-755) was an early concept.
The XP-819 Corvette prototype was introduced in 1964 by Frank WInchell and Larry Shinoda as the first, experimental, rear-engine Corvette coupe. The XP-819 was developed in the mid-1960's as an engineering exercise to determine if a rear-engine platform was right for the Corvette program. During that time, Chevrolet was still under a racing ban.