I did a port job on a freinds GTO and had good flow #s in the 550-575 lift range.We got 258cfm intake@550 lift and
[email protected] chassis dyno showed 491HP at the flywheel.The car is 3960lbs total race weight and has gone 11.50s in good air.The short block is 040 flat top pistons 0 deck,stock crank 4.210.Cam is a solid grind comp,cams around 565 lift.His short times are in the 1.60 range.Performer intake with 750HP holley carb.This car is very competitive and outruns his freinds GTO same year with ported E heads.Steel heads work with the right amount of porting and attention.