Highest Numbers on Stock Bottom End 6.0
My NA stock GTO LS2 bottom end made 436 rwhp with BES ported heads, SUMLSGT108 cam (less than optimum), 1.75" headers and 2.5" exhaust with flat plate transitions between mids and cat back. This was with a K&N typhoon intake and a Weeks tune. The heads had the intake bolts hanging into the ports .5" as well. With proper exhaust, rocker bolts ground to the ports and a good CAI I think it was good to 450 - 460 rwhp.
My GTO ran 12.5's on good traction on the street.
My GTO ran 12.5's on good traction on the street.
