I have a 99jeep grand with ATC. I have recently went for a ride in a 2004 with ATC. I noticed the Air condition blower moves so much more air than the 99 model. The 2004 feels like a wind storm when the cabin fan is on high while the 99 sends a breeze. I noticed there was an improvement to the hvac in 2002. What did they change to make this improvement? I am going to take a guess and say it is the heater box design. Does anyone know if the years are a direct replacement? I see they changed the evaporator design as well but it looks exactly the same except for the connections. Has anyone used the newer design box and the older evaporator. I really need to get more airflow out of this air condition?