Hi I saw on another post were you had offered to send a PDF of the factory service manual to someone .. could I get in on that too by chance? I have a 1998 ZJ 5.2 that has given me more problems than any vehicle Ive ever dealt with. Currently trying to find some good wiring diagrams but figured it was time to get the FSM if possible.

...the manual will tell you how to identify exactly what size pistons you have now ...there s a lettering system..since you already tore it down why not just ream the ridge and pop it out, bring it to a machinist..will need to press the piston on to the wrist pin and conn red...there are some that will come and install it for you..many leave this part to a machinist..

You are looking for what is called the factory service manual. Has everything you need. I have one I downloaded for free, for a 1998 grand cherokee, with the 6.0. many jeep owners and registration stickers actually have the wrong year as I found out with both my jeeps. so I thought the manual was for the wrong year, thought I had a 97, but then found out its actually a 98 from the vin number. So the fsm is just what I need. You can buy them, search on the forum or google "fsm cherokeeforum" which works better than the search on this site. I think they download for about $7.
If you get stuck I can try to email you mine its in PDF..but its huge.

Yepper thats what it was the ear off the piston was gone right up to the rings.Mite you have the specs for the engine.