can i do this? well it make any differences? i have the si intake manifold fuel rail and tb with injectors, si ecu, and si tranny on my hf motor but still seems really slow, wondering if i can swap an a6 or z6 head on the hf block?

 

no, the hf bottom end has only 2 valve relief cuts, you need four.

 

have you seen the ports on that head??? the exhaust ports alone are about the size of a quarter! and yeah...i would guess that the hf pistons don't have enough valve reliefs cut in them. for the amount you'd spend on a z6 head...just get the rest of your a6 swap (head, block, etc.)

 

go single cam zc

 

thx guys

 

i second to that