I would suggest elongating the bellhousing bolt holes in the proper direction to bring the bearing retainer hole into concentricity with the crankshaft centerline, then drilling the bellhousing and the back of the block for drive-in guide pins once the alignment is established properly. That should be a "one time" operation unless it's necessary to remove the bellhousing again for some reason.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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