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, GM enlarged their small-block V8 again to 350 in³ (5.7 L) and the ZL1 option was offered, with an all aluminum 427 big-block engine listed at 430 horsepower (320 kW) but generally accepted as delivering at least one hundred horsepower (75 kW) more than that. [citation needed] This option cost $4,700 (the ZL1 was a $3,010 option that consisted of an assortment of aluminum cylinder block and heads on top of the $1,032.15 L88 race option.), and only 2 were ever built.