General Motors introduced the High-Energy Ignition (HEI) ignition system in 1975. A huge advance on the traditional points-type distributor, the HEI distributor eliminated the wear issues and poor high-energy capacity of breaker points to produce higher levels of spark energy at a constant output over a wider RPM range.

45 years on, is an HEI system still a good choice? A modern system like a Davis Unified Ignition (DUI) HEI distributor can be a viable alternative to a Capacitive Discharge ignition:

One of the biggest benefits of running a DUI is that Performance Distributors gives every distributor a custom advance curve based on your engine and vehicle. They get a hand-fitted weight and spring assembly and are dialled-in using a Sun distributor machine. T

he precision advance curve provides instant throttle response and maximum power throughout the rev range with no pre-detonation. Other ignition manufacturers just give you an advance curve kit, leaving the task of setting an advance curve to you.

DUI HEI distributors are available for the usual Chevy, Ford, Chrysler, AMC, Buick, Olds, and Pontiac V8 engines.

Summit Racing also carries service parts and replacement coils for DUI distributors, plus ignition coils, spark plug wires, rev limiters, and other ignition components to get the most out of your DUI distributor.