Originally Posted by Caballerokid
I'm just worried that the 72cc chamber won't be as efficient is all. I'm ok with running them if they won't hinder anything. I'm shooting for 400-450hp and 450tq at max rpm 6k. Right now as sad as it sounds, i'm making 250hp and 317tq on a mustang dyno with 34 degrees timing all in by 3k and some detonation with the 882 heads 1.94/1.60 valves and basic performer intake. Peak hp was at 5300 and tq was at 3200. It quit pulling because it couldn't flow anymore air. They heads/cam stalled. Making that much more tq over the hp, it wants to make power but just cant breathe well enough to make more power.
you can hit 450hp at 6,000 rpm running on 87 octane, the way you're going is about the hardest most costliest way to do it.
Get a set of heads with about a 195-210cc intake runner, a good set with a good chamber. You'll only need about 9.5:1 compression, a plain old RPM intake, a 750 or so carb, good 1 5/8" headers with a good exhaust, and a hydraulic roller cam with about 225/230 duration and all the lift you can find (even a solid flat tappet cam will work if you're pressed for money).
To be honest I'd either consider selling what you have and starting from scratch or at least selling the pistons and swapping in some plain old flat tops.
You can hit your goals with a bone stock junk yard long block if you can find one with flat top pistons.