Another thing to consider....
IF your block main journals were line bored during the build, it is common for the rear main seal area to be cleaned up along with an main journals, causing additional clearance not expected from stock rms bore specs.
This happens frequently and requires a special oversize rear main seal to take up the slack after machining.
Ask your engine builder about this, and find out of you need one of these oversize rear main seals...
Jim