[JeffMedved]

Radiator is brand new (aluminum 2-rows 1 inch tubes). Flow-kooler water pump and RobertShaw 195 degree thermostat. Engine was rebuilt about 1500 miles ago. Car seems to run fine until I turn on the A/C and when I get to city stop and go traffic, it gets hot (to the 'P' in temp and beyond.)

The A/C is causing the overheat issue(s). I had the system converted to R134a and was wondering if that might have caused the issues? I am dumbfounded on what the cause of this is and where to find a solution. I am pretty much out of ideas.