Whats up guys/gals?

What are the aspects of insuring a properly "squared" (lack of better word) engine geometry? I bet there is alot, I have searched the net but came up blank (did get stuff on jet, turbine, and rocket engines though lol). How do you calculate this stuff? And how do you insure that she is indeed "square" (besides having all lengths of the block equal, all blocks I guess would be "rectangle" huh? lol ) Does anyone have a link they could post that would lead me in the general direction?

Thanks a million,
-Chris