Excalibur from Milwaukee, Wisconsin, was one of the first "retro" cars introduced as a prototype in 1964. The car was (loosely) styled after the 1928 Mercedes-Benz SSK by Brooks Stevens.
The Excalibur prototype was fitted on a Studebaker chassis and using a 290-horsepower Studebaker 289 V-8. As Studebaker subsequently ceased its operations, ending the availability of its 289 V-8 Excalibur was left without a power plant. General Motors friends Ed Cole and "Bunkie" Knudsen agreed to provide Brooks Stevens with Chevrolet 327 s in 300-bhp Corvette tune, making the light weight Excalibur a strong performer. They also designed a new ladder chassis which had a 2 inch longer wheelbase. The suspension components ere borrowed from the Corvette, as was the four-disc braking system. The Excalibur was born.