I just went out to look at a few of the pistons. What I saw was discoloration but I can’t feel any pitting. I’m not dismissing the possibility of detonation damage, I’ll need to look closer. Water did sit in a few cylinders so at some point, aluminum stuff tends to change color and texture as a result. This engine had been sitting for 2-3 years ( covered) in a region that gets light snow so I expected some cleanup would be part of the deal.
I’ll get a closer look tomorrow. Thank you.