I'm losing patience.. Carb or fuel pump issues?

[Jimbotronics]

I know some of you have answered my quetions concerning carb issues over and over - now I see what's happening but can't figure out why and it's driving me crazy. The carb is fairly new - purchased from a board member. Shortly after installing I couldn't get gas to stop running into the bowl after I killed it and had the carb totally rebuilt. It seemed like that was the problem because afterwards it didin't do for a while. Now it's doing it again, it'll even die coming to a stop if you don't keep the engine reved. I checked the fuel pressure and it reflects about 5.5lbs. Could it be that the pump is bad and is intermitent? What I do know is that I've got $300 bucks invested in a used carb and I'm ready smash it and I'm not even sure it's the culprit...