71 Dart A/C car heater issues

UPDATE:

The heat is/was working great. Got on the freeway this morning and hammered it pretty hard, got the rpm's higher than usual. The heat was working great up to that point. Seemed to be cool after that. Do these vacuum systems not take too much vacuum? Can i rebuild the actuator or soneone point me in the right direction of a new one? Ill pull the glove box out on my way home today and see how its working while im driving.