Sounds like timing to me. Re-check your point gap/dwell because new points wear in quickly and need to be re-set during break-in because the rubbing block will change quickly at first. Double check your timing, with vacuum spark advance line disconnected and plugged. Sometimes, they'll run better with more initial advance than the book calls for, so it can be a little of the trial and error method until it starts running good. Also, put a little vacuum on your vacuum advance cannister and see if the points advance (this is more for fuel economy than for performance).
