3d Model Conversion by: GeroDa74, Updates by Mac Ten

All Aluminum Small Block 388ci

In 1962 Duntov initiated a program to produce a lightweight version based on a prototype that mirrored the new 1963 Corvette. Concerned about Ford and the Shelby Cobra, Duntov's program included plans to build 125 examples of the Corvette Grand Sport to allow the model to be homologated for international Grand Touring races. After the GM executives learned of the secret project, the program was stopped, and only five cars were built. All five cars have survived and are in private collections. They are among the most coveted and valuable Corvettes ever built, not because of what they accomplished, but because of what might have been.

The cars were driven by famed contemporary race drivers such as Roger Penske, A. J. Foyt, Jim Hall, and Dick Guldstrand among others. Dick Thompson was the first driver to win a race in the Grand Sport. He won a 1963 Sports Car Club of America race at Watkins Glen on August 24, 1963, driving Grand Sport 004.

The Corvette Grand Sports were raced with several different engines, but the most serious factory engine actually used was a 377 cubic inch displacement, all-aluminum, small block with four Weber side-draft carburetors and a cross-ram intake.

Body panels were made of thinner fiberglass to reduce weight and the inner body structure 'birdcage' was aluminum rather than steel. The ladder-type frame utilized large seamless steel tubular side members connected front and rear with crossmembers of about the same diameter tubes. Another crossmember was just aft of the transmission and a fourth one at the rear kick-up anchored the integral roll cage.

The frame was slightly stiffer than the 1963 Corvette production frame and was 94 lb (43 kg) lighter. A number of other lightweight components were utilized to reduce overall weight to about 800 pounds less than the production coupe. Initially the Grand Sport project was known simply as "The Lightweight".