I drove my 1984 F150 about 20 miles then came to a stop. The transmission then was almost impossible to get into gear. I made it home now all it does is grind em when I try any gear. The clutch never slipped or smelled of a burning clutch. It goes into gear easily without the engine running. No leaks from the slave, master or hose and the fork moves when the pedal is pressed, though it's hard to tell if it moves far enough. Any ideas?

 

With a clear road in front of you, put it in 1st, step on the clutch, and start the engine. Does the truck start moving by itself? If so, the clutch is in fact not disengaging. If it doesn't move, it's probably a stuck pilot bearing/bushing. Either way, the trans has to be dropped and the bellhousing pulled.