Slo5oh

What is the stock comp thickness?
The common number seems to be .041

While were at it, does anyone know where I can find a gasket thats .021 thats not for a 4.16. Thats all I seem to be able to find for .021

Portmaster

Fords stock Gasket was .040 compressed thickness I think. I'd be looking more to getting the bore size of the gasket matched up close. I've seen some factory gaskets that were 4.150 across the bore. I use a 4.100 bore gasket because I have a .4.100 bevel at the top of my cylinder bore to help unshroud the big valves. Most gaskets will be either .040 or .041.

Slo5oh

Well thats the thing. Obviously Im trying to squeeze out another few comp points so the factory thickness won't do any good there.

Portmaster

I didn't see where you had edited you post to included the second set of information. I had walked away from my computer before I finished my reply. I assumed that was what your were doing trying to tighen up the quench area. The only fault in your plan is that by moving the heads down .019-.020 is the misalignment of the intake ports could cost you more than what you would gain in compression all dependant on how well your intake is already port matched to the head. But closing in on the bore size really helps the quench area as well. Sometimes it's not the compression that helps more than the burn across the piston. Take that open area out of the equation and it will have a better burn.

Slo5oh

Always a source of oversight correction. I plan on running an air gap with the new heads. I dont know how on it matches up.