look for faults in your ignition system, cap, rotor, points, wires, harnesses.
on the carbs see if you have a vacuum leak, let the car run on about 1500 rpm (adjust idle screw or have someone play with the gas pedal) then spray carb cleaner on the carb base, throttle shaft ends and carb body, if the idle increase then you have a vacuum leak at the spot where you sprayed at.