i deck all blocks why?? so they are square and the deck has the right finsh on it. new engines have a bad finsh on them and they will not hold the head gasket this gets real bad when the cr gose up. on a hp build i use the b.h.j blok- tru this make the deck rigth if the engine buider dose not go off cam and crank centers like the b.h.j dose the deck will not be at the rigth angle and if he set the boring bar off the deck the piston walls will be off. this is the start of a good build and rigth here is where to make it rigth. a good engine builder know this . if you have not done a lot of big blocks find some one with a good rep with big blocks and fine someone to do the work and get the parts from the guy so you get it rigth and use the stuff he like to use .this may help but this is the start. there is a lot of things to think about like oil clearance and the rigth length pushrods piston to wall clearance piston to vavles and a lot of things.