[RustyParts]

I may be mistaken, but I think the original wire running to the coil was a resistive wire reducing the voltage to the coil to around 8 volts, and there was also a yellow wire running from the starter solenoid to boost the voltage back up to 12 volts when cranking the engine to aid in starting the engine and as soon as the solenoid disengaged the voltage was reduced back to the 8 or so volts.

You can install a ballast resistor inline your present ignition wire to reduce the running voltage and add the wire from the starter solenoid to aid in the starting voltage. Also if you are melting the points the capacitor, mouted on the side of the coil bracket, is probably bad. It's purpose is to suppress the arc across the points when they open.

The HEI idea works too!!