Idle screw question. Rich or lean?

Thanks for all the advice. This carb should be close to what it needs in terms of cfm. The factory carb was an 1840c 600cfm. But made for emissions with a 2 stage power valve.

Car will just chug along at low speed no bucking. I can mat it pretty low rpm in 1st or 2nd rolling without any cutting out Now . It did before I put in the better pump nozzles holley makes. Still on pump cam position 1. I can literally idle through the neighborhood in 1st.

I'll get a pick of the vacuum guage. But the pony guys claim for a stock cam 18" is normal range.