in my opinion it ran rich/carb flooded gas diluted the oil and killed it, does not talk much fuel in oil make it useless, did it one and could not believe how quick killed one...

Machining the piston bores by hand with scotch brite and no piston clearance mite not be a good idea afterall. Never take your motor to a crack house to get built.

I curios , the pro systems carb was to blame, amongst you other problems?

you cannot just bolt on a carb and call it good...still needs to be dialed in with a wideband period, carb guys can get you close...and thats it usually. Worked on my blow thru a lot, and getting the AFR's right at idle, mid and WOT takes time, also have had issues with carbs flooding coming of plane, several holley based ones, I have always been running a elec fuel pump and now have a fuel pump switch the pump off for a few seconds coming off plane to keep anything from happening..would have saved a motor years ago...and back to these bearing/piston pics..still look like oil failure to me..

I see a couple Pistons that show signs of detonation. But as far as your main issue I'm with EZ on this one. Looks like oil contamination. If this is this case though the oil that came out of the motor should reek of gas. If you put your hands in it it should come right off and the inside of that motor should clean up very easily.

Negative on the gas smell. Oil had just been changed, had maybe an hour or 2 on it. In my opinion Pro Systems carb not at fault, just an overpriced, overrated mediocre carb that wasn't close out of the box and needed to be rebuilt with worthless customer service in my opinion. Boat had afr meters on it, was still being dialed in. Engines less than 10 hrs total run time including dyno. *12 qt pans as well, lots of oil

What specifically do you see that indicates detonation or oil issues so I can look into it? People that have seen the parts first hand aren't suggesting that. They are of the opinion it's due to the bores being both out of round and tapered, and / or too hot. Unfortunately piston to wall clearance wasn't checked, just the measurement of the bores after the pistons were out. Keep in mind this was a 9 to 1 engine running 93 octane making about 650 hp running at 5200-5300. Afr would just get into the 13s between about 3k-3500 then be in the 12s again. In the 11s at idle and slightly above

What's the chances you gas washed the cylinders during tuning? I have seen it before on a carbureted engine killed the cylinders from the choke staying on.
Where any of the second rings stuck?
Or it was lack of clearance piston to wall its in bad shape.
Now I see its carbureted from pictures.

My quick fuels were nearly spot on out of the box according to my widebands

I'm considering the possibility that heat might have been the main cause at the moment. There are obviously issues that the builder is responsible for like the poor rocker geometry and mismatched pushrods, but ultimately the failure may be on me. What if overheating caused the out of round bore issues ? Possible? What if the bores were honed with torque plates and then were measured after disassembly without torque plates ? could that cause the bore issues?