engine failure

I like to see @ 0.007" on 2 piece pistons with ally skirts and @ 0.004" on the 1 piece Steel pistons.
What I'm more looking for is "out or Round"

 

Did you have excessive blowby when it was running with the scuffed pistons?

 

I Only Use Plateau hone liners so basically minimal run in period.

What worries me is you have 1 Dead, another 1 breathing & one that is fine????

If you used the same parts on all 3 then the problem one would assume would be common to all 3 with the same symptoms. Assuming its a parts issue that is!
I'd like a Dollar for every time guys do and in-frame due to oil burn only to find no difference until they change the air compressor LOL.

What was the previous failure that required these rebuilds in the first instance?

 

Aftermarket pistons and a tuned engine are probably not a good combination, unlike cars, aftermarket internals for heavy diesels are gernerally designed as a lower cost repair option rather than to handle higher than stock power. As they say, you get what you pay for.
Having said that you'd want to be 100% sure of the cause before putting it back to work, be sure to do a coolant temp sensor sanity check, Cat has changed the manufacturer of their temp sensors in recent years and they are now ######, If the temp sensor is reading low the engine will overheat to destruction without logging a single fault code or even turning the fan on.
As has already been said, make sure the bores are round with a dial bore gauge before installing the pistons, rolled liner o-rings easily throw the bore out of round far enough to grab a piston, A long time ago I saw a set of pistons similar to this where the well meaning builder had put silastic instead of oil on the liner o-rings thinking it would help them seal, rolled o-rings on all 6, grabbed 6 pistons before the first oil change.