Wiring harness question

As some know my build is a mix of 78 KZ 1000 frame, ZRX suspension and a 81 J model engine. I need a wiring harness so I assume any harness from 77-80 would work , right? My brother used to wire aircraft so starting from scratch would be an option but I'm sure more expensive. Any thoughts?

You will ideally need the ignition and charging system parts from a "j" so it would make more sense to look for a good used "J" loom and adapt it to any earlier parts you are using (lights are lights and a horn is a horn so it will be the switch gear and instruments that will need adapting)

A complete Z1 900 wiring harness (175 $) would be a good starting point.

z-fever.de/shop/en/?cat=c140_KABEL-KABEL.html

 

I do not have a suggestion other than  what you need it dependent upon what all you want the electrical system to do?  Running lights, turn signals or just head and rear light/brake light? As Wookie indicated unless you are changing charging and ignition systems than a J model loom at least for those items would make sense.