Typically I set up my HP small blocks with a zero deck height and a .038 gasket for good quench. This works very well with ether open chambered X, J etc. heads or closed aluminum chambered heads like Edelbrocks.
I have run tighter quench. I normally do not like to push it so close. Top quality rods and attaching hardware should be used in this area. (Tighter quench)
I have been told that more than .050 quench is not good. The bennifit is lost at that point.