Thanks for the heads up on the gasket thickness difference. It would seem you need to cut the head ~ .040 just to maintain stock compression, let alone improve on it.
Actually you need to cut about .020 to maintain stock CR, when using an "aftermarket" head gasket. If you don't want to do any machining, use the OEM steel shim gasket. If you are going to mill the head, any way, just allow the extra .020 for the thicker gasket. I am running a head on my 66 Valiant 225, that is cut about .125 and the chambers are 39 cc's, and the shim gasket. This is a strip only car.
PS: Frank (66aCUDA) and I both have OEM stock steel head gaskets available.