I built a 240Z for autocross, hillclimb in '75. Rebuilt the engine nine times before getting it to 'stay together'. But, hey, 32 psi from a turbo. Ran AP. At the drags (once I finally got it to run the full 1/4 mile) it ran 11:98 @ 118. Such fun. Point is, as stated, build the engine first and you ought not have problems...under modest boost. Herb