the Dart stalled a few times while in gear at idle

When it dies, it just dies. No sputter or backfiring. When I turn the key it fires right back up, no excessive cranking or sputtering or flooding smell. It's essentially a clean stall and clean restart. Just as if I turned off the key intentionally and turned it back on intentionally.

I checked the gap in the distributor when I got it from you and it was fine. I will re-check it later today. I checked the connections at the HEI module and everything was secure.

Before I drive it I will take out the idle screws and squirt some carb cleaner down them. I'll also bump up the idle a little.

Sounds like a plan.