Thanks for replying Maria and being willing to listen to all of us fellow truck nuts - lol!
For others re-looking at your wiring question related to now using this switch, it's described as:
The Pollak 31-180P is a 4-position ignition switch with a die-cast housing, offering functions for Accessory, Off, On/Accessory, and Start, with a momentary start feature and a universal fit.
That switch should come with a wiring guide and IMO will work with your planned solenoid actuated starter, the 12volt new harness and the other electrical items you mentioned. Perhaps one of electrical guru's can better describe which wire goes were, etc. now?
Best of luck with the continued work on your truck!
