The HEI distributor is an inductive-discharge-style ignition, but with the points replaced by a solid-state switching device called an electronic ignition-control module.

Ignition-Control Module Test Testing the ignition control module is a little trickier. When the module is exposed to a specific heat range—which can vary—it tends to fail.

Our test engine is the same Chevy small-block used in the ignition test, so almost all of the stats for the engine are the same as listed there. The Performance Distributors HEI ignition was used ...

The GM HEI distributor is still a marvel of simplicity and reliability after four decades. Here’s how to maximize its performance on the cheap.