Black exhaust smoke

Hello, I currently Own a 1969 Ford Mustang, 302 V8 automatic transmission 60k miles on rebuilt engine. The problem started maybe 3 days ago when it wasn't starting right away like before, I always had to pump gas twice and then it will start fine. Well all of a sudden while driving after a stop light the car just shut off, I tryed to turn it back on and it and the only way to do so it will be by "flooring the pedal" and it will produce alot of black smoke and shake alot and then it will shut off after depressing the gas, I thought it could be the starter, I changed Starter, and the ignition solenoid. The problem was the same. I also changed the alternator and tuned up by changing spark plugs and wires, filters distributor cap and distributor, (since I have not done in the last 6 mos), the spark plugs were very dirty. I thought the smoke will go away and it did not :evil:. Could this be the carburator? :(