Benjamin T F:
Check the float level - common cause of fuel starvation - of course the most common cause of the symptoms you report are a problem in the high speed circuit in the carb.
If the coil was replaced with the correct one, you might have an issue with points/condenser breaking down under higher speed and like Nate said, timing could be on the ragged edge, allowing it to start and idle, but causing it to break up on acceleration.