1970 Dodge Dart 318 2 barrel Carburetor tuning

Seems like a rebuild may be in order. Start with pulling mixture screws and giving them a shot of carb cleaner,then compressed air. May loosen up the gunk.
Think you can use the vacuum from the pcv port.

Most but not all carbs have two ports, one above throttle plate and one below.

A couple photos would help.