Hello Corvette Forum,
Been a member for a while but this will be my 1st post. A little over 5 years ago I purchased a very used (UP) 81 C3 and I am now wrapping up a complete frame off restoration. The A/C is driving me nuts. I have read the many helpful post on the control valve and its inability to hold vacuum. I rebuilt my old one like some of the previous forums suggest, bought the "leak proof" one from Wilcox all to only fail and blow cold air out only at the floor. They all leak vacuum even after I rebuilt them again. I have now taken my small hand vacuum tool and applied a vacuum directly to the AC hose that goes to the actuator and get plenty of cold air out of the upper vents. I'm now considering installing some type of check valve at this hose and applying vacuum and just bypassing the control valve all together. Winters in NC are mild and the car is unbearable in the summer heat. Unless members of the Forum have any better suggestions.
Tired of wasting time and money on these cheap China made parts. (Old Spice)