Scored Main Cap Bearing - Ouch

As I stated before, check the thrust main side surfaces on the CRANKSHAFT. They should be flat without any grooves. A new thrust main with the correct undersize can be slid over the crank and then check the end play with a feeler gauge.

The one sided wear of the bearing could be from the crank being pushed out of position. I haven't seen any signs of a spun bearing.