"The third generation" of Corvette were produced from 1968 to 1982. The cars were patterned after Chevrolet's "Mako Shark II" (designer by Larry Shinoda). This generation has the distinction of being introduced to the motoring public in an unorthodox — and unintended — fashion.
1968 marked the introduction of Mattel's now-famous Hot Wheels line of 1/64-scale die cast toy cars. General Motors had tried their best to keep the appearance of the upcoming car a secret, but the release of the Hot Wheels line several weeks before the Corvette's unveiling had a certain version of particular interest to Corvette fans: the "Custom Corvette", a GM-authorized model of the 1968 Corvette.
In 1969, the 350 CID (5.7 L) engine became available in the Corvette, and in 1970, the 427 big block was enlarged to 454 CID (7.4 L). Power peaked in the 1970 and 1971 models, with the 1970 LT-1 small block putting out 370 hp (276 kW) and the 1971 454 big block having its last year of big power with 425 hp (317 kW). In 1972, GM moved to the SAE Net measurement for power (away from the previous SAE Gross standard), which resulted in lower values expressed in HP. Along with the move to unleaded fuel, emission controls, and catalytic converters, power continued to decline and bottomed out in 1975 — the base ZQ3 engine put out 165 hp (123 kW), and the optional L82 engine put out 205 hp (153 kW). Power remained fairly steady for the rest of the C3 generation, ending in 1982 with the 200 hp (149 kW) L83 engine.
Styling changed subtly over the generation. Minor trim changes occurred through the 1972 model. In 1973, the Corvette dropped the front chrome bumpers for a urethane-compound "5 mph" bumper but kept the rear chrome bumpers. In 1974, the rear chrome bumpers became urethane as well, resulting in the first ever chrome-less production Corvette. 1975 saw the last year for the convertible, which did not return until 1986.
In 1968 the "Sting Ray" name was not used, but returned in 1969 as a single word "Stingray" until 1976, the last year in which the name was used. In 1977, Dave McLellan succeeded Zora Duntov as the Corvette's Chief Engineer. 1978 saw a 25th "Silver Anniversary" edition, the first Corvette Indy Pace Car, the introduction of a "fast back" glass rear window, and the highest production number until the C-5. In 1980, the Corvette got an integrated aerodynamic redesign that resulted in a significant reduction in drag. In 1982, an opening rear hatch was offered for the first time on the Corvette available on the Collectors Edition model only. A new engine featuring cross fire injection, a fuel injection carburetor hybrid, was also introduced that year as the L83. It was the only engine available in 1982, and was not offered with a manual transmission.