Holley Engine Wiring Harnesses

A guide on how to install a universal wiring harness in a car. Read tips on properly wiring taillights, headlights, gauges, ignition switch, steering column and more.

In this Tech Tip, John answers a customer question about the Speedway 12 Circuit Wiring Harness.

Unbox our most popular wiring harness with Tim.

Making great horsepower on a budget is the LS engine family’s claim to fame, but just like any other engine, the more power you ask of it the more you’ll need to spend.

Read how to wire a lightning sprint engine. This detailed account of how to successfully wire an engine will ensure a smooth installation.

Comparing GM’s LS V8 engine to the high-tech LT V8 engine. Which is better for your performance needs and budget?

Learn about performing an LS Swap in a 1972 Chevelle in this tech article. We'll discuss lessons learned from our Chevelle engine swap using a 500-horse 6.0.

Fuel injection is here to stay and we delve into the benefits of such retrofit systems for your classic muscle car or street rod in our EFI retrofit buyer's guide!

Build a high-performance Gen V LT engine with proven power combos and learn about LT upgrades and tuning tips for maximum power

Speedway Motors just added some exciting new options to our line of racing harnesses.