Although the Tempest label wasn't used as a model name until then, Pontiac put early high-performance versions of the 389 on the option sheet with Tempest and Super Duty package designations.

The 326 looked much like the 389, only with smaller pistons and a light crankshaft. The 326 was the inaugural base engine for the Pontiac Firebird's debut, supplying it with 250 horsepower ...