If you’re not trying to stay vintage, original, check eBay for universal long hot rod harness. Don’t try to use it for 6v as it is lighter gauge (12v uses lower amps) you can choose number of circuits and flasher for turn signals. 3wire alternator would be my pick. Add relays for headlights and horn. Big truck you may have to extend taillight wires.Get a wiring schematic and try to stay close to the original run locations keeping the old wire in place, removing as you go. These guys will help if you get stumped. These old trucks are pretty simple…compared to.
