Originally, the HEI system was fitted with a four-pin module. By 1978, it had a five-pin unit. Seven and eight-pin modules were more a computer-controlled element that came around in the 1980s.

Car Craft tales you through the steps of how to convert a Ford or Chrysler ingition to a GM HEI for a high-performance, more-efficient ignition.

We analyze 10 common myths regarding HEI (High Energy Ignitions) distributor system including ones regarding internal coils, billet housings, performance gains, vacuum advance, and plug wires ...

So, if you burn a coil, chip the rotor, or create any other damage, consider rebuilding your own HEI distributor. Mallory's high-power module and coil are also compatible with stock distributors ...