There are three basic types of harnesses.
1. Specifically designed for your truck with original motor. It has the original style cloth covering and terminals. No fuses
2. Designed for your era of truck with modern wire and insulation. Like the one at Classic you mention. No fuses. Unknown number of circuits.
3. Universal harness with prewired ATC fuse panel, 12 circuit. Like
This one.
The universal harnesses all use the same quality wire. The prices are determined by number of circuits and extras and profit margins.
The older trucks did not have fuses much. Time to fix that with the kit no. 3. 12 circuits should be enough unless you have a bunch of accessories. I recommend the Speedway harness or equivalent prewired fuse panel type. If you need more circuits move to the Speedway 22 circuit @$189.
You will need to crimp various terminal contacts onto the ends of the harness wires as you route them to their connections and cut to length. We will help you sort it all out when you are ready.
Alternator. "3" Wire hook up.
Horn relay with screw terminals, much better than spade style.
The foot switch that Phil linked is what you need. . The Ignition switch is wired, as I said, to the ballast resistor on the fire wall, thru the resistor and to the coil positive. This gives the points a reduced voltage of about 9V so they last a long time. The starter takes a lot of voltage from battery during cranking and steals voltage from the points which are already only getting 9V. Soooooooooo....this side terminal foot switch, when foot switch is pushed, "bypasses" the resistor and gives the points as much voltage as possible during start. When you lift your foot as motor fires, the side terminal is shut off and the resistor takes over. The side terminal has a wire from it to the coil positive. So, two wires on coil positive.
Ignition switch usually gets it's power from a wire from the starter stud.
