When I did the evaporator in my Durango, I also replaced the heater core with an aftermarket and it only lasted a couple of years. I did paint the evaporator as it looked like the pin holes that developed because of the water and raw aluminum. Check to see how the blower motor is mounted. On my '98 Durango you had to remove the heater core box to replace it which I again had to remove the dash. I started getting good at removing the dash in that vehicle.