The 1963 Sting Ray production car's lineage can be traced to two separate GM projects: the Q-Corvette, and Bill Mitchell's racing Sting Ray. The Q-Corvette exercise of 1957 envisioned a smaller, more advanced Corvette as a coupe-only model, boasting a rear transaxle, independent rear suspension, and four-wheel disc brakes, with the rear brakes mounted inboard. Exterior styling was purposeful, with peaked fenders, a long nose, and a short, bobbed tail.
Meanwhile, Zora Arkus-Duntov and other GM engineers had become fascinated with mid and rear-engine designs. Duntov explored the mid/rear-engine layout with the lightweight, open-wheel, single-seat CERV I concept of 1959. A rear-engined Corvette was briefly considered during 1958–60, progressing as far as a full-scale mock-up designed around the Corvair's entire rear-mounted power package, including its air-cooled flat-six, as an alternative to the Corvette's usual water-cooled V8. By the fall of 1959, elements of the Q-Corvette and the Sting Ray Special racer would be incorporated into experimental project XP-720, which was the design program that led directly to the production 1963 Corvette Sting Ray. The XP-720 sought to deliver improved passenger accommodation, more luggage space, and superior ride and handling over previous Corvettes.
While Duntov was developing an innovative new chassis for the 1963 Corvette, designers were adapting and refining the basic look of the racing Sting Ray for the production model. A fully functional space buck (a wooden mock-up created to work out interior dimensions) was completed by early 1960, production coupe styling was locked up for the most part by April, and the interior, instrument panel included, was in place by November. Only in the fall of 1960 did the designers turn their creative attention to a new version of the traditional Corvette convertible and, still later, its detachable hardtop. For the first time in the Corvette's history, wind tunnel testing influenced the final shape, as did practical matters like interior space, windshield curvatures, and tooling limitations. Both body styles were extensively evaluated as production-ready 3/8-scale models at the Caltech wind tunnel.
The vehicle's inner structure received as much attention as the aerodynamics of its exterior. Fiberglass outer panels were retained, but the Sting Ray emerged with nearly twice as much steel support in its central structure as the 1958–62 Corvette. The resulting extra weight was balanced by a reduction in fiberglass thickness, so the finished product actually weighed a bit less than the old roadster. Passenger room was as good as before despite the tighter wheelbase, and the reinforcing steel girder made the cockpit both stronger and safer.
