point/eletronic ballast?

The single ballast resistor does nothing more than reduce the voltage supplied to the coil during run so coil doesn't overheat. My memory sux but I think most typical is a 1.5 ohm @ 68 degrees resistor and approx' 9.5 volts to coil. Resistance value and voltage pass will change some as this resistor does get very hot. Anyway...
Same coil, same ballast resistor. E-coil that operates on continuous 12 volts, no resistor required.