AC vacuum hose routing

[mikemileski]

I need some more detailed information than what's given on the attached diagram. First of all, I have a '72 GMC with factory air and a 350 engine. The only "vacuum source" that I can see on my truck is a solenoid looking thing mounted on the intake manifold on the passenger side of the carb. Only it has three vacuum nipples on it. One is on the backside along with an electrical connector, and the other two are on the front. If this is the "vacuum source", which one of the three nipples do I use to go to the vacuum reservoir and to which connection on the vacuum reservoir does it go to, the large nipple or the small? Also, exactly where is the Control Head Vacuum Switch located under the dash? If there's any Tucson guys that have factory air and would be willing to let me see their setup, that would be great. Thanks in advance for any help.

Mike Mileski
Tucson, AZ

(PS - I originally posted this in the 1947-1959 forum by mistake. My apologies)