Quote: However much power stock parts can handle lol...I have no interest in building a G3 hemi to only go and spend coin on Thitek heads. To me, the appeal of the hemi is how well the stock heads flow, both as cast and ported. Combine that with a good bottom end, and I can't see why 8-900hp isn't attainable.
I do want to stay 5.7 for blocks because of cost and availability....If the 6.4 head is really no good on that bore size, I will save my cash and put some work in to the stock 5.7 heads
Don't wast your time or money on the stock 5.7 heads. The Apaches are relatively inexpensive and will work on the 5.7 with the proper pistons.
You are going to have a really difficult time getting 8-900 wheel HP out of a 5.7 w/5.7 heads (even with serious head work). I really don't think you will be able to hit that number.
If you can't afford the Apaches try to find a set of 6.1 heads. We made 750-790whp on a completely stock 6.1 at 18psi on C85 - but that is really on the bleeding edge and wouldn't have lasted long.
As far as heads holding - the stock 6.1 mentioned above didn't come apart until 25psi and the factory heads w/factory head bolts and gaskets showed no signs of lifting. The failure appeared to be the stock rod bolts. Again, this is bleeding edge and only an experiment to see what a stock 6.1 could handle. That engine at 14psi powered the Jeep to a [Email]10.7@130[/Email] in Bowling Green - making it the quickest completely stock block Jeep on record.
Buy a set of 6.1 heads used ($900?) and freshen them up. Build a forged bottom or at least a 6.1 crank ($150) and some good rods and pistons. Have PWR spec you a turbo cam and put an 80mm on it. Then you will hit your whp number.
Will the Apache heads work with just a valvespring, retainer, lock swap, or do they need new valves also to run in higher hp applications?
What about the 5.7 eagle heads? I figure with enough boost per ci, 800hp should be a number not too difficult to attain.
Are the pistons necessary for the Apaches on a 5.7 expensive custom pieces, or are they becoming an "off the shelf" deal as of late?
With the deal on the 6.4 heads right now, I want to pull the trigger...I just want to know that they will be worth it knowing that almost indefinitely they will be going on a 5.7
