Ok so I took off the air cleeaner to clean up  and paint touch up a little and did not really pay attention to the vacuum hoses. Puting the air cleaner back on I have this hose that is not attached to anything and I cannot see where it goes? It is attached to the vacuum motor and leads to no where. The only thing I can figure at one time it led to the air temp sensor.? which happens to be missing. Yes I had a mechanic work on the carburator early on but would think this would have been addressed.I guess I was wrong, it must have been just hanging loose under the air cleaner.

Take the air cleaner off again and turn it upside down. Keeping in mind where the vac. line roughly ought to be you'll probably find where it goes.

HTH

Originally, there would have been a vac. line from the carb, up to the thermal valve("temp sensor"), and from there, another hose to the air door/diverter valve("vac motor"). If you still have the emissions decal on the firewall, it should have the diagram for the stuff...I think. I'm not sure when they actually started putting the emiss. vac line info on the decals....it may have been later than '78.
If the thermal valve is gone, then the diverter door ain't working anyway, so just remove the hose you have left. Make sure the door in the air cleaner housing is OPEN, too. They sometimes get stuck in the warm air position, so if you have the metal hose from the exhaust manifold to the air cleaner, you're getting hot air into the intake all the time.

I beleive this is for a 78