1970 Dodge Dart Heater/A-C Controls

I think if you want the old AC controls to regulate the heat for heater and defrost, you need to keep the vacuum line to the heater control valve on the inner fender panel, and retain the vacuum line that controls the opening and closing of doors in the box. I dumped my AC in my 1970 Dart in 1976 and have been using the vacuum controls ever since, even after I gutted the AC part of the box in 1998. The controls work fine for heater and defrost this way, but ALL the vacuum lines are still in place.