dist advance weights points vs electronic

I don't know much about Diplomats, and you didn't state the year. I know that in the early 1980's, many Chrysler's changed to a distributor w/ Hall-effect pickup with no advance (neither weights nor vacuum). Spark advance was done in the "spark computer" (aka "lean burn box"). I expect those distributors would have a different connector, probably w/ 3 wires.

I second the nylon gear installation. When I was a dumF kid, the nylon gear broke but only because my dumerF brother dropped a nut inside the distributor and didn't tell anybody (jammed shaft). I bought a new gear, but for some reason figured the rivet on the shaft was supposed to fit in the slot on the end of the gear. No, that slot is supposed to face down and the rivet go thru the hole in the gear. Maybe only half-dumb since I recall reading later that gears can come w/ no hole and one is supposed to drill the hole. Anyway, it actually worked fine and I got it timed that way. But, the rivet later popped out of the slot stranding me on the highway. Put it back, but eventually broke the nylon, so finally bought a rebuilt distributor and said "so that's how it fits". The real dumF thing was touching the car without having a manual. The internet makes all this so easy today.