I know this subject has been hit long and hard on this board and I've gathered lots of info, but I have one more question. I have a 2001 Wrangler and want to put a OD in it. I cannot do the AW4 conversion unless someone knows how to change a PCM so the old style PCM off the trannie donor can work with the new generation of PCMs found on the 2001 and newer vehicles. Does anyone know about the 42RE or 45RFE trannies found in the newer Grand Cherokees? Will these trannies bolt up to the 4.0 and a NV231 or would I have to use a 242 Selec Trac or 247 Quadra Trac as well? I am trying to stay away from the Chevy 700 route b/c I don't want to spend thousand dollars on adapter plates and all accessories.

Do the AW4 it is almost a bolt on. I'm in the middle of it now. There is a seperate Trans control unit for the AW4. IT should work fine for a 98-2001 trans and TCU. Just to be sure though, I'd try and find a 2001 XJ AW4 and TCU.
I'm putting a 2001 AW4 in my 97 TJ. You need a 98 or newer trans and computer for the computers to be compatable in a TJ.
Any questions, shoot me an email.
Scratch