Pontiac Models
With the introduction of the GTO in 1964, Pontiac created what was arguably the first muscle car: an intermediate car with a large engine. In fact, GM had a corporate policy which didn't allow anything larger than a 330 in these A-body vehicles, but the Pontiac engineers circumvented this by offering the GTO as an option package on the Tempest rather than as a distinct model. The option just happened to include the 389 engine, and the rest is history...