Original owner here. Car special ordered, and picked up Oct-1993. About 15 years ago I replaced the original ECM unit with the Mopar High Performance unit. I also installed Thorley Ceramic headers, K&N Air intake, a Demon ignition kit and a MagnaFlow Street Series Cat-Back Performance Exhaust System. My Jeep is well maintained and runs great. I now decided to go back to the original ECM unit, because I am tired of listening to 2,000 RPM to maintain 55-60 mph. Unable to locate my original ECM in my "archives" I decide to purchase an ECM from Flagship One. Here's the problem I need help with. Even though the ECM is based on the VIN, there happens to be three different ECM's associated with the 1994 5.2l ZJ, no matter the VIN. Various web sites have one or all of the three ECM versions. Flagship One asked for the part number on the orginal ECM of which I do not have anymore. A few dealers did not have the info based on the age of my ZJ. I also called FIAT/Chrysler support, and they gave me the three part numbers for the ECM's not specifying which one is the correct one. The part #'s are 56028112, 56028112, and 56029302. Can I have an assist fellow members as to which part is the correct part?