the Dart stalled a few times while in gear at idle

I just took the car on a drive to run a couple errands and no problems - as I said most of the time it's fine. I got home and with the car nice and warm I checked the idle RPM in park.....620

I think my ear was correct and the idle is way low. Whats recommended these days with today's gas in an automatic? 900? 950?

I do not have a helper right now to hold the brake pedal down so I can check the idle while in drive

i would maybe idle it up just a tad, and then revisit the idle mix tuning...
def tune idle mix when it's fully warm, maybe even do it in drive instead of park.
Great suggestion to set the idle mixture screws while the car is in D. I will do this next time I have a helper nearby. Currently the screws are 2 turns out. This morning I removed the screws and squirted carb cleaner down the openings.