65 barracuda headers

toolmanmike said
It would be interesting to see the numbers but I bet only a 8-10 hp increase at best. Probably $800? Just guessing. If we were running in the F.A.S.T. class it might be easier to justify.

According to this series of tests on a 440, extrude honed exhaust manifolds only added one hp at peak, although they did add 4-5 at low-mid range rpms. Buildup '69 440 Magnum Engine - Mopar Muscle Magazine