[Rick 427 Cobra]

I don't know what route you are going for a harness, store bought, custom or something from England, but this is what I did.

First you have to see were I came from. The attached pics show the original "professionally made for this car" harness. It worked as badly as it looked. The small multi pin connecters were under size and to my thinking there were too many connections and possible opportunities for failure. Same goes for the old fuse box. no less than 3 terminal strips. Way too much complexity and possible problems. pics 1 and 2
Everything was ripped out and I salvaged what I could. A new diagram was drawn up and revised more times than I can remember. Finally I posted drawings of each individual fuse circuit, in color, on the wall for reference. See background pic 3. A layout board was made using a dash as a template and labeled. I chose a non standard layout that put warning lights directly above the same gauge and was more symmetrical in appearance. A personal thing. I also went with a volt gauge over an amp gauge. Again safety. I used old AN aircraft switches with the radium tips.
All wires are full length with no connections except were necessary to splice for multiple uses(dash lights). All grounds are done by individual wire, no daisy chains.
40 amp relays are used to operate the fan, fuel pump, and horn. A load reduction relay is used for power supply to the dash, tail lights, wipers, instruments and an aux power port to remove any strain on the ignition switch. A VW headlamp relay is used for hi and low beams. I planned to use an electronic rear light splitter but it would not work with the LED boards I used in the rear lights. 4 relays were used to mimic the Lucas box. Should have just used some resistors in retrospect. The harness was wrapped in woven shrink wrap on the exterior runs. All connection were crimped, soldered, and shrink wrapped with plastic. New fuse box was labeled and the harness test fitted to a dash and smoke tested.