I was looking at the scoring in the bores. I thought bearings looked good except for the uneven wear and scotch brite marks. Might have been the flash making pistons look like that. Afr got into the 13s when cruising. Was in the 11 and 12s at all other times including wide open iirc

Oh yeah you detonated the piss out of that thing. Throw the valves away also.

One more thing you will see is the second ring will be pinched from the hammering on the top ring.

Afr got into the 13s when cruising.

I think that might be getting a little lean at cruse in a boat.
Plus you said it got a little hot that will also cause it to detonate.

The tops of the pistons look uniformly black and sooty to me?

I think some of what you're seeing might be from the camera. Look how different the valves look in the pics above and the different color on the pistons from last page to this page

Do the spark plugs have any black spots on them? Is your timing locked at 36?

Crane marine ignition boxes with the built in curve.

The 2 bottom pics at the top of the page most accurately show the color.

I tried to supersize the plug pic but it get blurry. Look for black spots on the porcelain...