1965 Dodge Dart Charger

I checked out the partsbook and it only shows chromed gas caps!!!

Correct. Service replacement caps were chrome so that they could be installed immediately on a vehicle of any colour.

I've seen painted ones as well.

Original-equipment caps were painted body colour.

Last year I sentmy alternator to Plum Crazy Garage and today was the day when the package showed up.

Wow, it surely is beautiful! Do you have the correct black plastic insulator collar for the output stud? Some companies list this as "1960-up", which is wrong. There was no insulator as original equipment in '60. In '61 a rubber boot (p/n 2258 754) was supplied as factory equipment early in the model year, with a TSB advising of its availability for retrofitment, which slipped over the ring terminal on the end of the wire. The insulating collar showed up for '62 (p/n 2291 093) and replaced the previous rubber boot.