[wkooiman]

I blew up a 351C about 15 years ago. It dropped a valve at about 5,000 rpms with a mostly stock bottom end. The pistons were cast, and they basically exploded - no kaboom, but there were aluminum bits everywhere.

Here's a pic of one of the rod bearings. It completely delaminated. That's all from one rod bearing - both halves fused together.

Maybe you have something similar going on with a bearing, but not as catastrophic as mine.

Here's the pic: