[Mike Taylor 3601]

I can't remember the size and don't have any on hand at the moment,but I think the size your holes in your block are the size that they opened up to when using BHJ products fixture.
BHJ dowel true corrects dowel holes off main bores,reams holes oversize to correct position.
I always use weld on bushings,easiest way to correct,I also use BHJ dowel true and surface bell area of block square to mains.
Mike Taylor 3601