Head Gaskets for a 340

[mj30wilson]

I have some heads for our 340 that have been machined and I want to lower compressor back to factory or below. Is their a rule of thumb for how thick a gasket has to be in order to lower compression considerably. I was thinking about putting a .075 compressed gasket on instead of thinner ones. How muh would this lower the ratio?

 

[Cranky]

How much compression does it have now and how much are you looking for? Here's a simple calculator if you know the details of the engine and cc of the heads...
http://www.csgnetwork.com/compcalc.html