Father-Son 1974 Duster Project

It's been a while since I've been under a Duster dash, but the harness should lay in looms made into the dash frame. I bet it routes over the steering column/brake pedal support also. The fuse box should mount to the firewall with a few screws, kind of up above the dimmer switch area. Here's a tip I learned years ago, that may save you some grief chasing electrical demons later on. Before you reinstall the dash frame, sand the points where it bolts to the door frame all the way to the metal. Do that to both the dash frame, and the door frame. Coat it with some electrical silicone grease like you put on battery terminals, and bolt it up. That will give your dash frame a couple of good grounding points. If you bolt it back up paint against paint, it might not make a good ground. The silicone grease will keep it from rusting. As far as the hole in the firewall, could it be for one of those plastic nail thingies that hold insulation?