Stroking the crankshaft to a most 81mm will preserve the RPM capability intact. Bores can be brought out to 83mm, but check out to help keep it less than 82.5mm. There's no will need for that System Atlantic crankshaft. Reject blocks that could have to have 83mm to wash up, obviously You can find head harm also.Stay clear of the 7AF to 7AG conversi