NO !! What you want to do is measure the current deck height and work from that. You also want to measure it at least at all 4 corners and make your calculations based on the shortest height. In reality, getting the decks square could end up yielding shorter decks than "zero" so you want to figure this out and work available gasket thicknesses into the equation.

As an example, in order to get the decks square on my block the pistons ended up .016 out of the hole. Luckily there are .051 gaskets !!