In 1973, Pontiac introduced the ultimate evolution of the 455, dubbed the SD-455, with a strengthened block, forged rods and pistons, round port cylinder heads, and a more aggressive camshaft with ...

Pontiac's 455 Super Duty was one of the brand's rarest and most impressive engines, but was it underrated from the factory? The post Factory UNDERRATED? Bone Stock Pontiac 455 Super Duty Hits the Dyno ...