stalling with AC on, coming off of idle

If your A/C system is overcharged and/or there is a restriction in the A/C plumbing it will make the compressor harder to turn, but what makes you think the system might be overcharged?

Is your OSAC valve still hooked up? That's the widget on the side of the air cleaner main body with one vacuum hose running to the base of the carburetor and the other vacuum hose running to the distributor. It is a hang-on-and-pray emission control device Chrysler put on to squeak the cars past their new-vehicle emissions type-approval tests so they would be legal to put on the market. Notorious for causing or aggravating stumble/stall on attempted acceleration, and the load of the A/C compressor can easily be enough to act as a tipping point.

Run the hose directly from the carburetor to the distributor, leaving the OSAC valve out of it. Set the ignition timing to 2-1/2° BTDC (a little advanced from factory spec) and put your idle speed and other carburetor adjustments back where they're meant to be. Check for general faults (vacuum leaks, gummed-up PCV valve, cracked/missing hoses, etc).

Tune-up parts and technique suggestions are in this post, and Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download.