The 4500 M1 intake worked pretty well with the 270 heads on my 470. The Wilson prepped Indy 400-3 worked better, but the Wilson prepped M1 4500 with standard ports worked really well. This was on the dyno. Going down the track the std port M1 might have been faster. I never tested in a car but it wouldn't surprise me. You should've bought these intakes from me when I sold them. I sold them for about half of what it will cost you to have Wilson port your intake.