89 to 77 front end swap-headlight harness?

[wraprail]

Keep in mind that pole 85 is just -Ground for the relay and does not need to go all the way back and connect to the headlight. Just run a short pigtail to the closest ground. The headlight should already be grounded.
You will only need one B+ wire and only one fuse since only one relay is powered at a time.. Just split it after your fuse and feed both relays.
Keep your fuse close to the junction block if possible. (18" or less)
The closer the relays are to your headlights the less voltage drop.
While this is true, I have not been able to notice any lower light output placing the relays near the firewall on my own truck. It has the relays placed under the dash and uses the factory wiring out to the lights. The biggest gains come from bypassing the headlight switch, dimmer switch and fuse block.