Did you try it without the seals and gaskets? did you try it without the thrust bearings? And does it lock solid? The bearings are all for the undersize crankshaft? Do you see any bright spots on the bearing, that indicates a high spot? Putting the pistons in will not help, just have to remove them again! If it still locks up, with seal and gasket off, and correct bearings, the block my need to be line bored to true it up!
Yes, bearing cap location has to be exact! Thanks.