This unit was removed from a '79 K20, someone has obviously been into it before, because the mounting bracket was bolted up wrong. Due to sitting out the elements for some time, the center shaft that drives the speedo cable was locked up. I opened it up to see what was wrong, it turns out that the shaft bushing was simply stuck. I got that freed up without much trouble, but the center of the shaft, where the square end of the speedo cable is inserted, seems to be badly rusted/corroded. Is there a source for these parts anymore? I haven't turned up anything yet. It's the piece that's laying on the ratchet.