Welcome to the asylum 3-speed is great because it is stout and you won't have to deal with burnout auto transmission or hard to find Quadratrac bits and pieces which is the transfer case that you have. On the 3-speed you have the Dana 20 transfer case otherwise on a usfs specs, bench is standard, so are the HD leaf springs, ooops, I see leafs replaced, so it probably a rough country kit.... make sure thst the nuts are not overly tight on the shackles
watch for your distributor being the prestolite w 2 vacuum control canister... known as preto no lite, but search here one member claims that it is an easy fix such as having good ground
and of course the ammeter bypass
Added FSJunkie solution for the prestolite
the post answer in the middle viewtopic.php?t=10761
Prestolite works great if you know how to fix it. 30,000 trouble-free miles on my own Prestolite so far.
You're problem is likely the module. One of the solder connections inside has cracked and breaks contact when it gets hot then makes contact again when it cools. Replacing the module for $35 is the easiest option, or you could melt the potting material out of the control module and resolder the connection. There aren't many components inside a Prestolite module, just a few capacitors, resistors, and transistors. You could probably build one from scratch with generic components. A good module will last 50,000 miles or more.
Sensors seldom go bad but they can get out of adjustment and hit the rotor. They should be adjusted to never hit the rotor no matter what vacuum is applied to the vacuum advance. The sensor wires are fragile and the electrical signal within is sensitive to the length and gauge of the wire, so splices and repairs must be handled with care to duplicate the original. Try to keep the sensor wires away from the spark plug wires and use dielectric grease on the connections to prevent corrosion.
A few drops of oil on the wick under the rotor will help prevent wear. It's a good idea to clean and lubricate the mechanical advance weight pivots and cams once every 40 years along with the upper bearing.
Carry a spare module and ignition coil with you.