Holley EFI Injector Harness

2005–2010 Dodge / Chrysler / Jeep 5.7L, 6.1L, 6.4L Gen III HEMI V8

558-211

Overview:

The Holley EFI Gen III HEMI V8 Injector Harness is a precision-engineered wiring solution designed specifically for 5.7L (2009+), 6.1L (2005–2010), and 6.4L (2011+) Gen III HEMI engines. This harness is essential for anyone upgrading or swapping engines who wants to take full control of fuel injection and ignition timing through Holley EFI systems. Whether you are enhancing your vehicle with power adders like nitrous, superchargers, or turbochargers, or integrating methanol and water injection, this harness provides the reliable, OEM-quality connections needed for advanced tuning and performance optimization.

Holley offers two types of injector harnesses: one with USCAR/stock injector connectors for use with factory injectors, and another designed for Bosch and Holley (Jetronic/Minitimer) style connectors commonly found in aftermarket larger injector setups. This versatility makes it ideal for a wide range of applications, from factory replacement to high-performance custom builds.

Key Features:

Designed to deliver precise control and seamless integration with Gen III HEMI engines, this injector harness offers:

• Compatibility with 5.7L (2009+), 6.1L (2005–2010), and 6.4L (2011+) Gen III HEMI V8 engines
• Support for Holley EFI systems to control both fuel injection and spark timing
• Two connector options: USCAR/stock injector connectors and Bosch/Holley aftermarket style connectors
• Capable of tuning with power adders including nitrous oxide, superchargers, turbos, and compatible with methanol and water injection
• TXL grade copper wiring for minimal weight and excellent conductivity
• High-temperature protective sleeve in a compact diameter for durability and neat installation
• Factory-style terminations ensuring strong, secure, and reliable connections
• OEM-grade connectors for a precise, positive fit to factory or aftermarket injectors
• Harness routed through split-loom braid for enhanced protection and professional appearance

Construction & Design:

The Holley EFI injector harness is built with high-quality TXL copper wiring, known for its excellent electrical conductivity and resistance to heat and abrasion. The wiring is encased in a high-temperature sleeve that protects against engine bay heat and mechanical wear while maintaining a slim profile for easy routing and installation. Connectors are manufactured to OEM specifications, ensuring a perfect fit with factory injectors or compatible aftermarket units. The entire harness is routed through a split-loom braid, which not only safeguards the wiring from damage but also provides a clean, professional look under the hood.

Installation & Fitment:

This injector harness is designed for direct fitment on Gen III HEMI V8 engines, including 5.7L (2009+), 6.1L (2005–2010), and 6.4L (2011+) variants. Installation is straightforward, requiring no modifications when used with compatible injectors and Holley EFI systems. The harness plugs directly into the engine’s injector connectors and the Holley EFI controller, simplifying the wiring process and reducing installation time. Whether you are performing an engine swap or upgrading your fuel system, this harness ensures a reliable and professional connection.

What's Included:

• Holley EFI Gen III HEMI V8 Injector Harness with selected connector type (USCAR/stock or Bosch/Holley style)
• Protective split-loom braid covering
• OEM-grade connectors and factory-style terminations

Ideal For:

This injector harness is ideal for automotive enthusiasts, professional tuners, and engine builders working with Gen III HEMI V8 engines who require precise fuel and spark control. It is perfect for those performing engine swaps, upgrading to Holley EFI systems, or installing power adders such as nitrous, superchargers, or turbochargers. Additionally, it suits applications involving methanol or water injection where reliable injector control is critical.

Holley EFI delivers standalone engine management and EFI systems built for everything from engine swaps to serious horsepower builds. With platforms like Sniper, Terminator X, HP, and Dominator, Holley EFI is aimed at enthusiasts who want modern tuning control, data, and drivability—whether it’s a street car, track car, or full-on race program.