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

Yup, what he ^^ said. The dead giveaway is that it runs better when the choke is closed. That says it’s starving for fuel. Likely the main circuit has trash in it.
I’ll try that and let you guys know how it goes. Weirdly, after turning up the idle to 1250, it fell back down to 1000 after a day of sitting. I really don’t know. But I’ll disassemble and soak in some carb cleaner.