305 upgrades?

[Gmc-76]

Originally Posted by motornut

yup both trucks are true duals,but (79-305) has an H pipe,both @2.25,no Ejunk really

Is there really a noticeable difference in the power? I know my tuck has all the emissions junk, a cat, a muffler with single in dual out, and I don't know if I were to put true duals with flow-masters and ditched most of the emissions crap if that would affect my back pressure.