To me it looks like the clearance was tight. When I say clearance, we've found when the crank moves those particular bearings need to be looser. The number 3 main only feeds one (#4) of the "bad rod" bearings. Maybe some taper in the #1 rod journal as well. Are all the journals the same diameter and straight? all the rod bores the same and round. Are all the rods still straight? How much clearance did they have? That's what I would be checking. My sons turbo 360 cast crank pics on the #4 main. That main runs now slightly over.004". Our bet is the cast crank looks like a jump rope under boost.
Doug