I think the #3 main bearing trash mostly went into #4 rod and some of that material may have been caught a tiny bit by #3 rod
I'm really surprised that none of the main bearing trash from the center main bearings wasn't wash into #5 rod bearing also
Did the motor have at least .0040 or more thrust clearances new?
Was #3 main bearing straight with no taper front to rear on the clearances?
I've seen between .0002 to .0004 taper on some of the new main bearings with block that had been align honed with new main caps and studs