Like DADS50 says, sure sounds like debris in the needle and seat, or some float issue.
The B carb is super simple, and there are great instructions in the shop manual for checking the float level etc.
I've never had a two barrel carb so I can't comment on them.
I have had a hole in my B float, that made gas pour out of the car like you describe though. Bought a new float for $12 at the FLAPS. Other than that, the B that's on my engine right now has been trouble free for 12,000 miles.
