This applies to 70 and newer cars
1968-9 cruise control is much different as there is a vacuum throttle release switch vs the electric throttle release switch.

Cruise control was a dealer installed option starting in 1970. Section 8 in the factory service manual.

There were kits to fit the various body styles. I have never seen 69 and back cruise kits but that does not mean they don't exist.

All mopars from 70-80 are wired to accept cruise control. Plug and play. It's not hard to piece together a system and it works well, taking the drudgery out of driving old iron.

There is at least one six pak car with factory type cruise control besides my former six pak car with owner installed factory cruise.

This is correct including the hole in the throttle linkage for the lost motion link pivot pin. One difference from most factory set ups is a pivot pin with a clip retainer was used vs a roll pin as seen on 99% of installations.

I can't remember where this pic was taken. The intake looks like cast iron...