I appreciate all the suggestions guys. I finally got some good gauges and had some time to do some checking this weekend. Just a few more notes about my system in particular. The shop that worked on my truck did not replace the filter/drier which is mounted up front by the condensor. The filter/drier does have a sight glass, which I cleaned, but really can't see anything in there. The refrigerant is 134a. I do have the heater cut off installed and that shuts off the water flow to the core when the system is set at MaxAC. The door in the plenum that shuts off the outside air flow in order to recirc inside air does appear to be closing as you can hear it "thunk" closed when setting the knob to MaxAC. Vacuum lines seem to be in good condition and I don't hear any leaks or see any deteriorated vac hose. I also checked the drain hole in the evap housing and may have found part of my problem. I noticed it was dripping but wasn't drippping much. I stuck a wire up in there and took a shower! A lot of water drained out of there - that could not have been helping the cooling! Isn't it amazing how simple stuff like that can get ya. I then hooked up the gauges. It is about 80° here today. With the truck cold and shut off: low=82/High 82. I then started the truck and at high idle and the system still cold the low=8/high/120. After 10 minutes run time and revving the engine to 1800 the low dropped into vacuum at -2 and high dropped to 105. Going back to idle , the low went back to 18 and high to 150. Vent temp went as low as 60°. This is just with the truck sitting in my driveway with no electric fan blowing over the condensor. Revving the truck again after about 5 minuted to about 1800, the low was 4 and high 160. Returning to idle, the low was 18 and high 155. The high side line at the compressor is very hot with the low side line only slightly cool. The expansion valve at the evaporator is pretty darn cold and sweating. I hape I have provided enough info - I appreciate any help you guys can offer, Thanks - Todd