Ideas on what's causing my click/tick/rattle noise?

Timing and detonation didn't do that to those bearings. I really have a difficult time buying into that, especially since there's zero evidence of detonation on the piston tops. I think it was a simple assembly error (no offense) or a possible part failure, or maybe some trash in the engine in the oiling system. If that engine detonated enough to beat bearings out of it, you'd see evidence of it. There is none.