For stock engines, I've heard a gasket thickness of .040" is used. I also read that stock height is 9.025". Assuming this is actually true and mine is 9.005", would I need to use a .060" head gasket? Or would the recommendation be to stick with stock .040" and happily accept the small increase in CR?
I guess I am looking for confirmation from experts that a 0.040" gasket thickness is typical for stock, and that 9.025" is the stock "0" height for decks and if a change in gasket thickness is necessary when you deviate from this.
TYPICALLY, stock GM pistons are in the hole .020-.035 on small blocks. Not sure if it was explained to you, but when a block deck is cut , its normally cut parallel to the crank centerlines, from there you determine your rod lengths, then piston compression heights.
If you are looking to increase compression and what most race builders mean by " blue printing the block" this is what is considered.
If you add a thicker head gasket , like a .060, you are basically lowering your static compression. If you are doing all of this on your own math , you will be fine running a thinner gasket like a .039 or the GM type steel shim of .017-.019, but remember, you do your homework, trust your math . If you are already at .005 in the hole and you go for the thinner gasket say .025, I feel thats cutting it too close for a street car. Best to err on the high side of your piston to head clearances.
Another factor is to pay attention to what your cam lifts are as they play a part in this game and I don't think you are in it , yet.
Here is one compression calculator, but there are many out on the internet. https://www.yourmechanic.com/article...pression-ratio
If you use the .060 gasket and your known in the hole is .005, you can safely say you are running a .065 piston to head clearance.
This does not take in account of piston rocking in the bore so as I mentioned before, do your math , if you want to increase compression in a simple way.
Its simple if you can understand it. Here is another calculator tool. http://www.diamondracing.net/tools/
I might add that to use some of these calculators, you need to know about the piston and its specs as wells as rings, bore, etc. Enjoy.