1966 Plymouth Valiant /6 & Holley 1945 carb can only get to idle at 1250rpm. How to get a lower idle without dying?

I would go back to AJs post #22 I believe it was and follow thru.
Have you ever pulled the gas tank and check for rust/trash/dead bugs and the pick up tube with sock filter? First thing I do with any project. And the line from tank to fuel pump.
Metal fuel filters are safer but the plastic ones let you see the gas level in there.
As said before, choke closed more and it speeds up mans it wants a richer mixture.
Coming behind any one can be a cluster**** that has "tied" to work on an old car.
Like you just said, you can have issues with electrical inc. distributor. Thats another ball game..

Working on old cars that run like c*** is like needing a GOOD doctor that can diagnose whats is wrong with you! If he wants to just start cutting off your parts and pieces, you need a better doc!
That’s my problem, I’m not a good doc lol. I haven’t pulled the gas tank. I daily drive it. Some good news!

FFFUBAR carb FTW!
I swapped the carbs and now have it idling at 750. It looks ugly but it’s doing a better job than the nicer one, not sure for how long though. Gonna give it a test drive.