If I am incorrect of what steveo is talking about, please advise.

Basically quench is the distance from the flat parts of the head to the piston. Let's say your engine is assembled with the piston .010" down from the deck(deck clearance). If you use a standard .038" thick gasket, you will have .048" quench. Most hot rod people try for .035" - .040" quench. The desired quench can be done with deck machining or gasket thickness.