[dynoroom]

I t seems like the block may have been decked more than 1 time or decked a bit much. eather way deck height is the amount of clearance between the top of the piston @TDC & the deck of the cylinder head. This is usually .035- .040 with steel rods. This includes the head gasket. Example, piston @ .000 deck, gasket @ .039 thickness (Fel-Pro type), would give you a deck height of .039. In times past Ford would run the piston @-.018 down the hole with about a .022 thick shim type head gasket giving a total of .040, Simple!
Hope this helps, Mike