I am building an 87 octane 455. The block will be zero decked and otherwise built mild. Maybe spring for some cheap H beams and I will include forged pistins and moly rings. Of course, everything else will be rebuilt as well.

Anyway, a buddy suggested some 6X heads milled to the cc I need for the compression I want to run. Question is, what heads exactly? I have a '75 intake, but I want to go with a unit that is a little better flowing. Am I going to have gasket matching issues?

Thanks for enduring all the questions!!

Dave

I have a set of 96's..96 CC. 9.2 to 1 on a 30 over 455. 9.4 to 1 with a zero deck.

They are large valve screw in studs. Heads will be disassembled, baked, shotblasted and magnafluxed by Friday. All small parts cleaned and reassembled. They will likely need a rebuild. Off a 71 GTO.

The 6X 4 heads would work very good. No gasket problems with Edelbrock intakes. Here's a 'ready' set on eBay:
http://cgi.ebay.com/ebaymotors/Pont...617QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I have 6X #8's on my 400 right now, if your looking to buy shoot me a PM and we can talk.
I have been looking to swap out to some different heads so if you buy these from me, I have no choice and I can buy a set from Banshee

Now the question is how much compression can I run with a mild cam and not have detonation issues? I would prefer to NOT take a bunch of timing out to control ping.

Dave

9.5 to 1 properly carbed and timed/curved dist. Some guys run higher on 93 with no problems. Most larger duration cams have lower cylinder pressures and one can get away with more compression

Stick to 9 to 9.5 and 93.

I build my engines as from factory and run only 104-110 octane. There are others that run their motors at the threshold of detonation that can really get detailed.

You can go several ways with the rebuild..

96 heads 96 cc chambers 9.2 to 1 with SRP 10-12 cc piston standard deck 455.

6X or 5C heads 6.7 cc piston. zero deck

Those 6X-8 have 112-114 cc chambers (455) or 98 cc 400

Why zero deck? Why spend $$$ on H beams. Resize stock rods with ARP bolts, you'll do just fine. Not like you are ripping up mad with an 87 cc low compression motor.

I agree on the rods. I have concluded this will be a low rpm motor and the money is better spent elsewhere. Zero decking just to help with combustion issues. I don;t know why, but it made a heck of a difference on the last two motors I have had. I was told it was a flame front/ travel issue with Pontiacs. Am I wrong for doing this on this motor? It's ready for the machine shop, just not gone yet.

Since we are talking sompression, heads, ect. What is a good economy piston that won't weigh a ton?

Thanks for the info guys! I really do appreciate it!!

Dave

Economy and weight do not go hand in hand.

Weisco and Ross make the best, lightest piston. $580-650 set.

Speed Pro is economy and weight.

http://store.summitracing.com/partdetail.asp?part=TRW%2DL2359F&autoview=sku

PM Sent.

Dave

Back at you.

If its going to the machine shop, may as well deck it.
Not much extra, and every bit helps.