Vacuum advance is a topic that many hobbyists avoid like the plague. Most summarize its perceived intent into a single function—a way to increase fuel mileage. While it's true that vacuum advance can ...

Which came first, the chicken or the egg? It's an ageless debate, lacking a definitive answer, yet both sides are strongly supported with opposing theoretical views. Many agree that its automotive ...

It wasn't all that long ago that GM engineers designed the original HEI system to replace the decades old points-type ignitions. In the mid-'70s, leaner mixtures demanded greater voltage and more ...

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 ...