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Vehicle Info Needed558-310 HEMI Coil Adapter Harness Early Model Coil (Coil that requires spark plug wire)
Ships on 11/03/2026
Lowest Price Guarantee- HEMI Coil Adapter Harness
- Early Model Coil (Coil that requires spark plug wire)
- For use with Holley HP EFI & Dominator EFI ECU
Chrysler has used two different coils on the HEMI engine series with 2006 being the year that the change was phased throughout the truck and car line. Fortunately the two coils are very different visually and makes for a simple review. If the coil requires spark plug wires, it is the early coil. If the coil does not require plug wires and simply has two boots that connect to the plugs in the cylinder head, it is the later coil. View the image gallery for images of both types.
For coils that require spark plug wires. The HEMI's Variable Valve Timing is not supported by the Holley EFI systems at this time. You can run an engine that is equipped with VVT, but the cam timing will revert to the mechanical default. The Holley R&D team is working on an accessory harness that will drive the VVT actuator. However, it is not available at this time. The HEMI's Multi-Displacement System (MDS) was primarily designed for fuel economy purposes and does not need to be connected when switching to a Holley EFI system. NOTE: Not legal for sale or use on pollution controlled vehicles.Emissions Note:
This part is only legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles or on vehicles used solely for the purposes of closed competition racing.
CLICK THIS LINK FOR IMPORTANT CARB & EPA EMISSIONS INFORMATION ABOUT THIS PART
Harnesses to Install a GEN III Hemi in Your Hot Rod
Take control of your Gen III Hemi with Holley Wiring Harnesses capable of controlling fuel, spark, transmission, and more.
See More
Simplify your Gen III HEMI swap with confidence using Holley Gen III Hemi Wiring Harnesses—precision-engineered to deliver maximum performance with minimum hassle. Whether you're working with a late-model 5.7L, 6.1L, or 6.4L HEMI engine, these plug-and-play solutions make integrating modern powerplants into your project car easier than ever.
Designed for seamless compatibility with Holley EFI systems, these wiring harnesses offer clean routing, factory-style connectors, and labeled wires for effortless installation. If you're tired of splicing factory looms or chasing down wiring diagrams, Holley’s harnesses eliminate the guesswork—helping you get your build on the road faster and more reliably.
Each HEMI stand alone harness is tailored to work with specific Gen III configurations, ensuring accurate sensor readings, proper ignition timing, and optimal fuel delivery. The result? Better drivability, improved tuning capability, and a professional-level finish that’s ready for the track or the street.
Whether you're upgrading a classic Mopar or customizing a restomod, a 5.7 HEMI stand alone harness from Holley delivers the performance foundation your project demands. Built with durability and flexibility in mind, this harness stands up to the demands of high-horsepower builds while maintaining a clean OEM look.
Take the hassle out of modern engine swaps. Choose Holley for reliable wiring solutions that save you time and keep your project moving forward. Order your Holley Gen III Hemi stand alone harness from JEGS today and bring your HEMI-powered vision to life.
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HOLLEY
554-113 HP EFI ECU ONLY Drives Up to 16 Low or High Impedance Injectors Includes USB cable and software
Part Number : 510-554-113
HOLLEY
Part Number : 510-554-113
