Chevrolet W Motor

There's a lot of parts variety with these engines! In cylinder heads (left to right): the 348 passenger-car (casting #379) type needs bigger valves and some port work for good performance; the '62-65 409 truck head (#333) has better ports, but the same smaller valves like the 348, the right piston is needed to raise compression; the '63-65 340hp 409 (#817) has good flow and bigger valves; the best factory head (#690 or #583) for 380-425hp 409s, very little work needed to support 550 hp; the new BWR aluminum heads from Bruneau with high ports are like the best 409 head but 40 cfm more flow on both sides and can accept 2.25 intake valves. (Photo courtesy of Bruneau Performance)

Vintage Engines: Chevrolet's "W" Motor

There's a lot of parts variety with these engines! In cylinder heads (left to right): the 348 passenger-car (casting #379) type needs bigger valves and some port work for good performance; the '62-65 409 truck head (#333) has better ports, but the same smaller valves like the 348, the right piston is needed to raise compression; the '63-65 340hp 409 (#817) has good flow and bigger valves; the best factory head (#690 or #583) for 380-425hp 409s, very little work needed to support 550 hp; the new BWR aluminum heads from Bruneau with high ports are like the best 409 head but 40 cfm more flow on both sides and can accept 2.25 intake valves. (Photo courtesy of Bruneau Performance) View Related Article

Chevrolet W Motor

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