bearing failure after rebuild?

[Irasthmus]

Hi guys, I recently rebuilt my 20V silvertop, but at 250km into the wear-in, I'm getting bearing noise. Everything was done to factory spec with OEM parts except the bearings, since the Toyota dealership weren't going to get the OEM bearings in a resonable time so I opted for aftermarket ACL race bearings for the 4A-GZE which is supposed to be the same (they have the same OEM part numbers).

The tear-down is supposed to start next week so I'm taking the time now to educate myself on what could cause premature bearing failure, especially on a recently rebuilt motor.
What tell-tale signs on the bearing surfaces and the crank that I should look out for that will indicate what went wrong (if it was installation error or driver error or oil/debris issues)? What do the markings mean?

I'm also posting this to ask advice on what my options are for repair. Do I need to look for a crankshaft since my old one was already polished (not machined) for the rebuild? Is there a slightly larger size to be used in instances like this, like say a '3' instead of a '2' as was recommended by the rebuilder? Should I stick to OEM this time or try another brand/size of aftermarket bearings?

I'll be present for the tear down to ask questions etc. but I want to know what to look out for so I'll know what questions need to be asked.