[ta man]

Originally Posted by Steve C.

Regarding the primary pipe diameter for your street/STRIP application your bias should be toward making more top end while sacrificing a LITTLE down low.

Also note if your cylinder heads are ported to 315 on the intake and the exhaust port is left untouched the exhaust-to-intake flow ratio will only be about 58 percent. This based at 0.600" lift. Due to the amount of energy (heat) lost during the combustion process, a basic ratio of 75 to 80% exhaust flow/size to intake flow/size is a viable target. And yet some suggest exhaust port flow numbers are about useless in the real world.

Also if left at 58 percent some will suggest adding additional exhaust duration on the cam choice.

Do your homework on the subject.
.

Going from my flow numbers on my heads SD is right at 75% after port work. At .400 272.2/205.3 75.42% at .500 300.6/226 75.18%