on the deck height ...if you dont assemble the engine...you can only guess at where the pistons will be in relation to the deck since the deck height on a factory engine will be all over the place...now if you take the block to the machine shop and have them square the block...then by doing the math on your crank...rods and compression height on the piston you will be in the ball park...then again....unless your rods have been blueprinted..and the crank has been index and stroke equalized....there will be some variations...