You'll be pulling the rear cap on and off, and same with the crankshaft, about a dozen times to get everything squared up. My joke about the bearing cap being cast by pre-Industrial Age Druit priests after an all-night ale binge pretty well sums up the primitive casting quality. The answer to your question depends on just how awful the backside of the bearing cap is and how much metal needs to be shaved off. I took the cap into a shop for the initial grind, but ended up finessing the final fitting myself with a belt sander. The key is to get a square, smooth base surface for the seal housing. Motorbill66 does his grinding inhouse, as he has a nice industrial belt sander that can be trued to 90 degrees.
Be really careful with the flywheel bolts and alignment pins. If they protrude forward of the crankshaft flywheel mounting flange, they might contact the seal housing, making short work of all your efforts ... Been done several times apparently.
And a "Been there,. didn't work" tip - Install the timing chain cover with the front lip seal installed, first. Then "offer up" the sump. Don't forget the little oil slinger disc on the front of the crankshaft, otherwise the front seal will leak.
Compared to the casting and machining standards of a modern engine, these old XPAG motors give new meaning to "automotive archeology" ...