[ddsmith]

I second GMC Jim's opinion. I had some stuff missing from my A/C system when I purchased the truck. I ended up installing an Old Air unit and wish I had just done what was necessary to make the original work properly. The best part about the original is that the evaporator is larger than the aftermarket units and you maintain your original control functions. Conversion to R-134A isn't that bad either. The POA needs adjusted but any mechanic can handle that task with the information that is available, the drier/receiver should be changed, oil changed to work well with R-134A. If your going the R-12 route then take the certification test so you can purchase it yourself legally. R-12 is still pricey but a bunch less than a shop will charge you.