84 should have mechanical linkage, adjust for 1 inch freeplay at the pedal. Nut to turn is near the bellhousing boot under the truck. Service parts were still available from Mopar perf as a E/B body clutch parts kit, but I think that was disco'ed.
The return spring pulling the arm back from away so the throwout bearing had some space was notorious for breaking on these as well so check for it.

As for hydraulics, pretty sure 1st year overall from factory was 87s with a 6 cylinder, then they all got it in 88. (trucks)