Hi, new guy here. I am working on a car for a friend and it has been a long time since I have owned my Chevelles and I'm stumped. When I opened the hood I found a vaccuum line that was not connected to anything and for the life of me I cant figure out where it goes. The car is a very clean 1971 Chevelle SS with a 350, air and 4 speed. I beleive it is an actuator possibly for the heater controls but I could be way off. It is located just behind the alternator on the passenger intake mainfold. The line is very thin in diameter and seems to be routed to the passenger side top of the wheelwell. Any and all help is appreciated and thanks in advance-John.

P.S- I cant seem to get a picture to attach to this. I could Email a pic to anyone willing to try .Reply to mullen_john@sbcglobal.net Thanks

There are several possibilities. One is that a vacuum line on top of the engine would be for spark advance. And if you have an orphan hose, it might left over from TCS (transmission controlled spark) when someone did away with that feature. That would be my first preference.
Another possibility is that the hose for the heater's water valve has been disconnected. That hose comes out of a grommet on the firewall just behind the RH cylinder head. In that same grommet is the hose from the vacuum check valve that supplies vacuum to the heat/ac control head.

The second possibility may be correct, although the existing vaccuum hose there that goes into the car has only one port and it does not appear to be disturbed and looks original. Thanks for the reply-John