We may all ponder this small mystery while you enjoy the benefits of pulling and capping off this mystery hose, Wes. We may all be thankful that the peak of the emissions vacuum hose jungle syndrome was way back in 1985. Next time in a junkyard, have a look underhood at cars from the late 70's to mid Eighties. Even if the engine is gone, try to find a vacuum hose diagram decal . If you do, marvel at the awesome complexity. Some of these buggers look like a London street map.
I once did extensive work on an '84 Honda CRX. Cool little ride, and it had a 3 bbl. carb. There were many vacuum hoses and vacuum gizmos, and it had this big black box full of vacuum solonoids, with un-decipherable purpose. So as a warning to others, I labeled this thing "Pandora's Box" in multi-colored model paint.
Tracy G