interesting car craft article this month on GM modules

66plyValiant said
power to the coil still comes from the car not the HEI when switching to that setup, so in that case it would be a full 12 volts to a coil only meant to run 6.5-7 volts with a ballast

In all reality the ballast was really, originally designed to give longevity to points in the distributor.

I know, I know, flame away. :D