Piston Question for 96+ XJ's

I was wondering if I could use the 95 and older pistons in a new 4.0 (96-2000).
I am assuming they are diff weights, thats why I would be putting in all 6 and not just replacing one. My bro blew a hole through one out of his 96 H.O. motor and its been hell trying to find a single replacement. Does anyone have any suggestions... Summit sells the Fed Mod. Speed-Pro Hypereutectic pistons, but Im pretty sure they are not the same weight as a stock piston. Does anyone have a single 96-2000 piston they would like to sell. Or does anyone know where to get a single stock replacement piston... my local dealer (Troncalli, was asking $145 per piston!!!) Also someone told me the 2.5l I4 uses the same pistons as the I6 throughout 96-2000. Any suggestions or help would be greatly appreciated, thx.

they have the same bore but different ring sizes.

stock replacement pistons should only be about $20 or so.

his head is probably cracked too.

www.rockauto.com around $27. Did he fix the condition that caused the hole in the first place?

We haven't done much but opened it up after a couple cylinders weren't firing... I believe his head may be warped after he overheated it quite a bit one day... Guess he didn't pay attention to the temp gauge ... anyhow I noticed lots of antifreeze in 3 of the cylinders when we cracked it open... Fluid in the cylinder under compression is my suspect for the hole in the piston (either from antifreeze, or him sucking water in on a trip not to long ago) as you can tell hes pretty rough on his jeep, anyone have any input?

uhhh yea, rebuild, reman, or junkyard

Yes, you can use the older pistons. The bore is the same but the pistons are slightly different. They are not metric like the newer pistons so the rings are not the same thickness. I think NAPA should at least be able to order singles.
Try this number, just looked on the website. Piston w/ Pin: CEP
2242322

I wouldn't even mix up pistons in the same engine let alone from a different one.

Read the post... I wouldnt even consider mixing old and new in the same motor, I was keeping the option open of pulling all 6 out-- to keep it at a budget because we found a donor motor (1995) with a decent set of pistons and rods. I can get the older style rings from a buddy for pretty cheap. Ive done the research so I know about the ring sizes and all, just wanted to see if anyone had any experience in doing so before I made any decisons...

Are you going to be doing anything to the cylinder bores in the new motor, or just throw in a set of used pistons?

Being that they would be used... I wouldnt do any work on the cylinders, just new rings for pistons (std.). I was just going to try and get it running for the time being. Though I talked to a guy earlier today that has a 4.0 out of a 2000 XJ with low mileage... I have made the decison to go with the newer 4.0. Anyone know much about using the distributorless ignition system in a 96 XJ? I am assuming I would have to swap over the harness and ecu... any input on that. If I am not able to obtain the harness and ecu is that 2000 motor capable of running a distributor?