I'm not an expert. But, I would say setting the points by smooth idle is risky. Retarded timing (but not too so) will give easy start and smooth idle, but can also give you misfire/backfire at higher rpm's. If I misunderstood your post and you did set the points with a feeler guage I apologize. Point's change dwell and timing, but dwell does not change points. If you have the points set correctly, then dwell is automatically correct. Once points are correctly set, then set distributor timing with a timing light. Anyone, please correct me if I'm wrong.