98 XJ Questions???

I have a '98 XJ 4.0 4x4 and unfortunately it has Crapifornia Emissions Equipment on it. I was wondering if I were able to switch the PCM to a 49 State Emissions PCM? Are they interchangeable? I live in Tampa, FL. so we don't have emissions testing. I was comparing my XJ to my best friends '98 XJ who's is a 49 State vehicle and they look to be the same but his is more powerful. We both have 1 cat and 2 o2 sensors. Does anyone know the difference between the emissions equipment? I know the California computer is detuned compared to the Federal PCM.

Should be able to swap in a Federal PCM after having the VIN flashed. It will work regardless of the VIN flash.

What is the purpose of the VIN Flash? When they flash the VIN does it change the tune?