Here's What Made The Pontiac 421 Super Duty Big Block Engine So Impressive
It shared its cylinder heads with the 389 Super Duty V8, and was topped with two Carter four-barrel carburetors. The 421 was ...
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The Highest Rated Horsepower In A Pontiac Car In The '60s
The 421 Super Duty engine's exclusivity and extreme performance ... Pontiac ended up offering the powerplant as an ...