Wiring is one of the most time consuming jobs you'll encounter, hopefully your harness is intact and all ya gotta do is hook everything back up, some of it will be just common sense and you'll see where a lot of the connectors go, BUT you need to be armed with a wiring diagram,
Do not use crimp connectors on anything,
only soldered connectors & joints with heat shrink tube where ever ya can use it.
I'd send ya a wiring diagram if I had it but my stuff only goes back to 1980.
I can help ya a bit with grounds, Neative battery cable to the engine block, headlamps usually ground to the core support, the dash circuits usually just ground to steering colunm support, you need a ground strap from the engine block to the firewall, and a lot of folks including myself like a ground from the engine block to the chassis..