The heater core in my MJ is starting to go and I want to pick up a complete HVAC unit to rebuild. I had to repair a few pieces on mine and I rather replace it with a better one.
I'm not sure if the box is different, but I'm in the process of replacing a heater core in a 99. There is no cable for the blend doors...it is all vacuum. I recently took a 98 apart and it did have the cable. This might effect which box you need (cable or not).