[Gaz64]

I'm surprised it has only one big end cap discoloured.

I would say EVERY bearing is damaged, and I agree with what others have said, there will way too much damage inside there.

Your "engine builder" doesn't seem to know how to assemble a high performance engine.
The valvetrain is the best example of this, find a real engine builder who understands ALL the clearance checks to perform during the mockup assembly.