If you still have the plugs for the 83 dash, it should be a simple as splicing them to the EFI harness. Get wiring diagrams, and have at it one by one. Only problem I see is that your early model dash will probably not have a Check engine light. You will have to rig something else up for that. Check at the truck repair shop for an engine light that mounts through the dash. I am on the coast if you want to bring it to me.
