Electronic ignition for Slant 6

The ballast depends on the coil and the characteristics of the ignition box. I don't think either Pertronix or the old Mopar have any current limiting. A GM HEI module works different. It is much more complicated. For one, the HEI, and I'm referring to GM HEI, NOT the Holden/ Skip White/ ready to run/ import stuff-------the GM modules do NOT DRAW CURRENT when the key is on with the engine stopped. So this protects the coil and module

Also, the HEI has some sort of variable dwell control?? which limits coil current. I ran an HEI module with the factory stock Mopar coil and no ballast. Made much hotter spark than the Mopar ECU and did not hurt the coil.

Depending on the coil, I would for sure run a ballast with Pertronix