If your car has factory AC under the dash I would try and leave that there and upgrade under the hood to a newer pump. The harness for AC is and add on to a non AC harness. There is a spot in the fuse box for it. All the controls in the car are vacuum. except for the fan and the pump.
i will get a few pictures today, the AAW harness goes into the firewall but will not allow the air box on inside of the car to sit against the firewall. so if i wanted to "modify" the air con side of the unit s that possible?