Sometimes a feeler gauge is not held flat and will cause a larger gap than you think it is. As Jerry said smaller gap= larger dwell. Go by what meter says. That's why Chevy had the window on the dizzys. I love that for setting points to a meter.
Also I assume you have new points. New points MUST be examined and tweaked so that the contact pads are concentric and flat to each other. You do this by "bending/twisting" the fixed contact side of the points. NOT the lever side. Many points are cheaply made and, if not aligned, (calibrated) will be hard to set and give bad performance. The flat spring must also be spot on, not too strong, not too weak.
Bottom line is ALWAYS, how does she start and how does she run? Don't mess with mother nature.
