Originally Posted by hcompton
Lol how old is that article. They dont even make those 3 tubes any more. My three tubes from headman were way better than any manifolds and a few of the four tubes i tried.
So you're telling me you did back-to-back tests, w/ONLY the headers being changed? And you lost power w/which 4-tube headers?
More to the point, I DID
have occasion to test 3-tube Hedman aluminized "headers" against a set of Hedman 4-tube headers on a 400 Pontiac belonging to my friend and neighbor, Bill Anderson. '78 T/A, engine I built, had a cam from HO, #12 heads. It picked up 1.5 tenths- WITH ABSOLUTELY NO OTHER CHANGES, other than the runs were made one week apart. I'll be glad to give you his email addy should you doubt me.
When you learn why a 4-tube header works better than a shortie/block hugger/3-tube header, get back to me. Has to do w/the scavenging effect that a 4-tube has that's disrupted when using a 3-tube. The age of Hand's article is irrelevant- what's relevant that you choose to ignore is the big tube never "peaks", and if it DID, the rpm would be too high for the smaller pipes.