i'm looking for a pcm for a spare on my 96 gc with a 4.0 6 cyl...how do i know which one will work on mine?...is there a part # you can use for an interchange...i have been looking at a few and some are different in appearance...mine has tabs that hold it together and some look like they have screws that hold it together

 

Comically I just posted about the pcm on my 2000. Not sure if the same applies for your 96 but I do know for sure that with my 00 I had to not only replace the pcm but also the ignition and the security module around the ignition. Tried to just pop a pcm from another 00 into it and it didn't stay running. The only other thing I can advise is that you need to look for a pcm from a same year Jeep with the same options. may be easy may not be, idk how common your options are vs other 96 grands