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
I guess you are not getting what I'm trying to get across. The GM module, UNLIKE the mopar module LIMITS current to the coil after / or when the coil begins to saturate. The Mopar box has no such circuit. "It's just a switch."
A side note, you'll find that when the car is running/ charging, (factory system) coil voltage is more like 10-12 with the system voltage properly running about 14