318 Poly Flow Test

Earlie A said
Other people have gotten 250-260 cfm out of them. Even saw one report of 270 cfm. There are some strokers making 500hp. Cams and intake manifolds are expensive.

Yeah I've seen Gary Povlovich articles about them. The 4" arm for the 340 is a direct drop in. They can be made into stump pullers.