Only five original C2 Grand Sport Corvettes were actually built. Chevrolet had planned a much larger run, but the program ended before the proposed production total could be reached.
Zora Arkus-Duntov initiated the lightweight Grand Sport project in 1962 to challenge cars such as the Shelby Cobra in international racing. A run of 125 cars was intended to satisfy homologation requirements, making the number 125 a common answer to this question even though it describes the plan, not the result.
After General Motors executives learned about the secret racing effort, they stopped the program. The completed cars consisted of three coupes and two convertibles. Their lightweight construction included thinner fiberglass body panels, an aluminum inner structure, and a tubular steel frame.
All five originals survived and became exceptionally valuable collector cars. They raced with different engine configurations, and Grand Sport chassis 004 scored an early notable victory at Watkins Glen in 1963.