The demands for better emissions and fuel economy in the mid 1970s necessitated leaner fuel mixtures. These leaner mixtures required greater voltage and more spark to ignite. This challenge led GM ...

If you've been readingHPPfor any length of time, you likely recognized the importance of spark advance. Over the years we have reported through dyno and/or dragstrip testing the benefits of optimizing ...

Reliability, a simplistic design with many interchangeable components, and heavy support by OE-replacement and aftermarket manufacturers alike makes GM's HEI among the best executed distributor ...

At some point in the mid 1970s or so, GM (with Delco Remy) came up with a new electronic ignition system known as HEI or High Energy Ignition. We've touted this as an upgrade for many engines in ...