For your 97, its a lot different than the other era Jeep 'J' series (C,Y). Most of those had the space for an evaporator setup separate from the Jeep original heater plenum. I don't think there is enough space behind/under the dash in a TJ. For yours, I believe you will need a plenum from a TJ with the AC as an option. This provides the integrated evaporator in the plenum.