distributor mechanical advance

"Stock" covers a lot of ground. The factory specs are in the FSM, which you can download at MyMopar. Bear in mind those are distributor degrees not crank degrees. And on that note, if you refer to "other" charts, like, maybe, "Motors Manual" some of those may also be rated at distributor shaft RPM and NOT crank RPM

I don't know about MP. Some of those were of different manufacture, and SOME had Mallory type adjustable mechanisms. You can tell by looking closely "down through" the distributor.

Here:

MP Distributor Tuning Tutorial

mopar MP adjustable advance - Google Search