LOL...Chris remembered right,....
I aim for .038 to .040 (max) for deck height. Certain race motors that get higher compression will run .035 but thats really close.
I do not permit a deck height greater than .040 (1mm) since that really makes these engines more prone to detonation; something that all hemispherical-headed motors have problems with. Its worth the extra effort, IMHO.
Stacking two base gaskets (shims) is fine.