Welcome to EFI Connection
We specialize in GM fuel injection systems for SBC, LT1, and the variety of LS engines. Since 2003 we have been manufacturing brand new fuel injection engine harnesses for GM engines and offering replacement harness components for GM fuel injection harnesses.

Largest Online Inventory of GM Connectors
Are you looking for that hard-to-find connector for your GM fuel injection harness? Our online connector search will let you choose from nearly 150 GM harness connectors. No knock-offs here. We stock only Delphi, Molex, Bosch, Kostal, and Yazaki connectors to allow you to properly service your GM harness.

Modernize Your Early SBC, TPI, or LT1/LT4 Engine
Our 24x systems and 58x systems bring Gen III LS1 PCM control and Gen IV LS3 ECM control to these popular engines. In 2008, we pioneered a crank and cam signal solution for these engines to use the popular LS-based electronics. Our 24x solution is the only replacement to the troublesome LT1 optispark distributor and has enabled amazing potential for these engines; even 8,000 rpm capabilities!

As Seen in the Media
Our products and solutions have been demonstrated in popular GM performance publications such as GM High Tech Performance and Street Thunder magazines. See more at our magazine coverage page.

Building Your Own Fuel Injection Harness?
We offer online all of the quality automotive wire and unassembled connectors you will need to assemble or modify a GM fuel injection harness for your project. However, EFI Connection strongly recommends professional wire harness assembly with the correct tooling. But because of popular request, we are offering a self-service website for your convenience. Price breaks are available (and shown online) for low quantity purchases.