I wonder if the block was prepped properly? I've seen stuff put together without de-burring the sharp edge which forms at the bottoms of the cylinder walls. Any side thrust and the ally pistons would be shaved each rev'.?

Lots of pain and suffering in this thread.

Im doing my best never to feel the pain again. For me that means staying NA, doing my best with it and accepting it will never win dyno days, but in all other respects it does itself proud.

Good on you guys throwing money at power. (perhaps somewhat recklessly at times) Maybe one day Ill do an FI build. But I have zero time for it right now and see zero need.

Ill be wheeling the camaro out to the next track day, so bring all your exploding and non exploding vehicles along and try your luck. There is pint for everyone who beats my best time in road trim

The fact rings are pinched and jammed into the ring grooves suggests heat to me.
Certainly there would be no real visual on the head or pistons as far as heat goes. Aluminium does not discolour.

All LS engines have short skirts. It would be physically impossible to use pistons with long skirts otherwise they would hit the crankshaft and also the trigger wheel ( which my JE's did slightly as there wasnt enough clearance on No8 for the trigger. No big deal though. There was clearance when cold though, obviously not when running.)

And all LS pistons protrude beyond the bottom of the bore. Strokers more so. Again, it is physically impossible for it not to happen given the design of the engine.
And it's highly unlikely JE would make a piston so unsuitable for the application which is a very common one.

The only way you'll stop it happening is to buy a tall deck block and use matching longer con-rods.

Depending on what the skirts actually look like, the damage may have come from the bottom of the bore not being finished properly. This area needs smoothed so there are no sharp edges for the piston skirt to rub against. Again, common practice on an LS because ALL piston skirts do protrude beyond the bore.

Iam in Rich

Generally speaking, this is true but the finished bore is slightly inboard of the cylinder casting. Pistons wouldn't usually have issues here unless the side thrust was extreme at the time or unless a seizure was happening. As for pinching of the top rings in the top ring land, the piston compression/deformation will be from either heat, massively high cylinder pressures or detonation (high cylinder presures and shock waves). There's nothing above the piston so it's got to be one of them. This could cause a chain of events to happen, including piston seizure, destruction of an engine etc. Vertical scratches on the piston sides above the top ring indicate detonation as do craters, pin holes and grooves on the piston crown. If there aren't scratches or witness marks then I'd agree with the heat idea. Forged pistons are hard as nails, it takes quite a lot to deform them.

It's a crate unit, so as long as it's installed by a VAT registered garage, and isn't played with, then the unit is covered. Once you start playing with pulley ratios or ECU maps, you're on your own though.