I am out in the shop assembling the latest project which is a .060 over 440 for the wifes GTX. The short block is done and I used KB Hyper, quench dome pistons(#184) The block was decked and the pistons are .075 down as perscribed by KB.
The heads are 452's, stage 2 port by Muscle Motors(good trade!), probably been shaved a little in the past. Using a Fel-pro permatorque(new)which is supposed to be .039, I put clay in the quench areas of the head, oiled the quench domes, put on the gasket and head and torqued it to spec. I rotated the crank thru two cycles, took the head off, sectioned the clay and I have .080 clearance. KB calls .040 optimum and under .060 acceptable. I will be happy with .050. The question I have is, what is the optimal solution? It would seem that a steel shim gasket would minimize head milling to around .010, but would it hurt to just mill the head .030 and stick to the Fel-Pro comp gasket? I will have to have custom pushrods made anyway, and they will have to mill the intake side of the heads, it does not matter to me which way, but I am curious about which method is the best. Thanks! Lee.

me personally I do not like steel shim head gaskets(seen too many leak) while others are actively searching for them . .080 is no quench. I would use the felpro composition ones & mill accordingly to get .040 max. What I am concerned with though is on the 452's & other open chamber head the depth & slope of the open chambered recess can & does vary from chamber to chamber. Did they check/equalize them? I bet they didn't & since you are going to the trouble to get proper quench(which is doing it correct ) I'd check them & have them milled/equalized.

My reworked 452s varied quite a bit in chamber depth. My plan was to equalize them, rather than custom cut the quench dome for every cylinder...

I am going to use clay on everyone of them. With a depth mike, they were running .088-.090, pretty close actually. If there is no more than .03, that will be close enough, if not, flycutting the chamber may be the answer. I guess .030-.040 cut on the heads will cause no other problems?

Other than the intake needing cut, how does milling the heads that much make a difference when the valley pan gasket is installed?

I use the KB quench dome pistons in the .030 over 440 in my 63. Where you have me wondering is you say your piston is .075 down in the cyl ?? Here is where mine came out and my 906 heads had been cut .060. I checked every piston height and every combustion chamber depth. My pistons averaged about .023 down on the piston flat and the quench pad stuck above the deck about .055 out of the cyl. My head chambers were an average of about .025 deep. I used a .074 cometic head gasket and the setup came out to right about 10.0 comp. I have .055 of piston pad above the deck and I used a .074 head gasket so that is .019 of quench so far and when you add the .025 chamber depth I get an average of .044 quench. The chambers varied about .005 before I worked them and the piston pads varied about .003 difference. All of mine ran between .040 to about .045. and my 440 runs fine on 92 pump at 38 total timing. Ron

My 360 used the KB quench dome pistons and I had to mill the block and heads to get the quench right, plus do some slight clearancing on the quench dome because of the "eyebrow" near the intake valve on the head.
I just set it up to where I had nearly zero quench without the head gasket, then installed the Felpro 0.039" gasket.
Another issue I had was one head had a different distance fron the deck surface to the quench part of the head, so each head had to be milled different amounts.

Next time, I am just going to use flat top pistons.

Ron, I used the KB#184 piston. It calls for the flat to be .075 below deck with a .140 high quench dome. I was looking to end up with approx 9.5 comp ratio. I probably should have gone for more compression, but never using these before, I decided to err on the side of caution! These pistons are a bit of a problem to fit, but I was basically given a set of MM stage 2 heads and to get 9.5-1 this was the alternative to custom pistons.

Ok Lee now I understand as we use different pistons. Like I said my flat was .023 down with the pad about .055 above the deck. Or you could say my quench pad is about .078 high. Ron