1979 Other Ford Models Carb issues?

I really like this website.

About a month ago, I purchased a 1979 ford Pinto 4 cylinder. I was told the mileage was 60,000. Hopefully that is correct and it's not 160,000. Anyways, when I first bought the car the carb was stalling the engine out. I had the carb "serviced, " which was really expensive and the car ran fine for about a month. However, lately it's been somewhat problematic.

When I start the car cold, the engine revs somewhat high, but nothing crazy. When I depress the throttle, the engine goes down to a normal idling speed. I typically wait 2-3 mins to let the engine warm before I toss it into gear.

When in gear, sometimes the car will idle fine, but sometimes the idle will be a little rough and feel like the car wants to die. Lately it has died a few times at stop lights. Today when I drove the car, I didn't experience any issues. However, I needed to restart the car immediately after driving it to repark the car. When I restarted, the car was idling rough and wanting to die.

I know there are a lot of possibilities as to what is causing these symptoms, but maybe should I buy a NOS carb and start from scratch, letting a shop install it rather than stick with the old carb I have now?

Thanks.