Starting to assemble but?

the main bore in the block could be big. also it could be the bearings, try the bearings from 4 in position 1. too tight would be a no no, hi performance / hi rpm engines go .001" per inch of shaft diameter. if it is the crank, and say it is .010" under, u can't get an .011" bearing, and the crank would need to go .020", no big deal. or run it, 1 bearing with .003" will only give u SLIGHTLY less oil pressure