But to the point made by Ignoramus, you don't want to be stuffing (technical term) a reamer through that, to try to re-size it or change the axis of orientation. The only bush you should do that to is a solid bronze bushing and even then, you should be using a boring head to machine the bearing surface. A reamer to adjust the sizing by a very small amount, if you think it needs it. Better to have the crank journal ground by a few thou to fit the bush.
Clearly, the factory thought you should just whack out the old bushing and beat in the new with a lump hammer, after waving a big hairdryer at the cases.
PS the timing side main in my cases doesn't look like that photo. Mine has the 'ears' on it that locate it in the case casting.
Last edited by S-NJ-W; 02/09/21 11:08 pm. Reason: Postscript