Do you even have a machine shop around that knows what they are doing? I just finished building a 400 for a guy here and its getting harder and harder to find parts. For instance, Hydraulic flat tappet camshafts are no longer being produced. Whatever is left on the shelf at a parts house is all that's left. Same with engine bearings, getting harder to find good -.010 and -.20 main bearings and rod bearings.