[slickster]

Remove the throttle cables and see if the throttle plates are hanging up, a dirty air cleaner won't cause your problem, neither will a sticking carb slide, it'll just make it run very rich, the throttle plates control rpm....check for vacuum leaks, you said that you held your hands over the intakes and the rpm's shot up, vacuum leak.....typically, sticking throttles are caused by bad cables more often than not.....if you have a bad vacuum leak and someone tried to compensate by cranking up the idle speed....it'll do that...also, if the idle circuits in the carbs are plugged and the idle was cranked up to compensate....it'll do that.....start with something simple, like old, nasty cables and go from there....good luck, Mick