1969 Dodge Dart Engine Stutter

So far as the battery you need to get it "up and normal" and run it awhile. It may be old, or sulfated, or otherwise damage, or it just still might be low. "Back in the good old days" we would have used a hydrometer. People claim that voltage tells if a battery is charged, but it is way too easy to get fooled by "surface charge." Once it is "up" fully charged you might have it load tested. Most anyplace that sells batteries or Oh'Really's can do this. IF the thing can be accessed check the water in the cells