These two big-block V8 engines were also the swan song ... the Chevy 454 produced less power than the Pontiac SD-455 at 275 hp and 468 lb-ft. Pontiac's 455 V8 was designed with one goal in mind ...

Pontiac joined the American big block V8 rivalry with its rare 421 Super ... The high-revving 421 V8 boasted impressive specs, producing 468 hp and bolstered Pontiac's racing reputation against ...