84 Chevy K10 idling high

Hard---to----say

My first guess is gummy, sticky, or bent choke/ fast idle cam linkage.

Can you tell, when it's idling high, if the throttle lever is hitting the idle speed screw? This is over on the driver side.

If you look at them carefully, engine off, you can work out how the choke linkage works and how it pushes up the fast idle cam. There's also a link in there that locks out the secondaries until the choke opens. That stuff is pretty much all on the passenger side.