That’s a Rochester B. You could try a couple things before you get your vac gauge. Turn the idle screw in and gently bottom it out. Turn back out 1.5 turns. That just gives a baseline to work from.
If the engine will run and idle, even if it’s rough, you can hunt for vacuum leaks by spraying something flammable at various places. Carb base gasket, intake manifold gasket, etc. if the idle smooths out or picks up, that place is leaking vacuum and needs addressed. In other words, it’s pulling the spray in through a leak in that area.
Some folks do the same thing with an unlit propane torch.
