It seems crazy that just by connecting the exhaust pipes you gain 12 - 15 rwhp.
Has anyone slapped in an X pipe and noticed a difference? Could you even notice a 5% increase, or is that something that would only show up on a time slip?
'71 GTX N96 auto 3:55
'74 Challenger 440+6 4spd 4:10
'71 Duster 340 auto 4:10