Late A headers on an early A (smallblock)

Huh? who said anything about a 318 with little mods?

That was directed at the second poster, not you.

Just some info I saved, don't know if
it helps any.
Just getting it out there so it can be found again.

Appreciated but again, you can put the largest exhaust you want on a car but if you don't do any mods to intake side of the engine it cannot breath in more to expel more. The graph only shows changes made to the exhaust but nothing to the intake side of things. You need to make equal changes to both intake and exhaust to really see a difference.