HOLLEY EFI 558-505 Modular Valve Harness Kit 090127721377

( Brand: Holley Efi ), ( Part Type: Valve Harness ), ( UPC: 090127721377 ), ( Manufacturer Part Number: 558-505 )

Review HOLLEY EFI Ford Modular Valve Harness Kit

The Holley EFI 558-505 Ford Modular Valve Harness Kit is a high-performance solution designed to provide reliable and efficient fuel injection for your Ford Modular engine. This harness kit is specifically engineered to work with Holley's 558 EFI systems, offering a plug-and-play solution for your Ford application.

The kit includes a complete wiring harness that features heavy-duty, color-coded wiring for easy identification and installation. The harness is designed to connect the EFI system to the Ford Modular engine, fuel system, and various sensors. It includes all necessary connectors and terminals for a simple and straightforward installation.

One of the key benefits of this harness kit is its compatibility with a wide range of Ford Modular engines, including those found in applications such as the Ford Mustang, Mercury Cougar, and Lincoln Mark VIII. It also supports both EFI-only and carbureted applications, making it a versatile choice for Ford enthusiasts.

The Holley EFI 558-505 Ford Modular Valve Harness Kit is built to the highest standards of quality and durability. The wiring is made from high-temperature, flame-retardant materials to ensure reliability and safety. The connectors are designed to withstand the rigors of high-performance applications and are sealed to prevent moisture intrusion.

Installing the harness kit is a straightforward process, thanks to its plug-and-play design. It includes detailed instructions and diagrams to guide you through the installation process step by step. With the Holley EFI 558-505 Ford Modular Valve Harness Kit, you can expect a seamless integration of your Ford Modular engine with your Holley EFI system.

In summary, the Holley EFI 558-505 Ford Modular Valve Harness Kit is an essential accessory for any Ford Modular engine enthusiast looking to upgrade to a high-performance EFI system. It offers a reliable and efficient solution for connecting your engine to the EFI system, with a plug-and-play design, easy installation, and compatibility with a wide range of Ford applications.

The Holley EFI 558-505 Ford Modular Valve Harness Kit is a popular choice among Ford Modular engine owners for upgrading to electronic fuel injection. Here are some pros and cons to help you make an informed decision:

1. Improved Fuel Economy: With electronic fuel injection, the engine receives exactly the right amount of fuel at the right time, resulting in improved fuel economy.

2. Better Idle Quality: The kit comes with an adjustable idle control feature that allows for a smoother idle and improved driveability.

3. Easy Installation: The harness kit is designed to be easy to install, with clear instructions and pre-terminated wires.

4. Wide Compatibility: The kit is compatible with a wide range of Ford Modular engines, including those found in the Mustang, F-150, and Explorer.

5. Improved Power: Electronic fuel injection allows for more precise fuel delivery, resulting in improved power and torque.

1. Cost: The Holley EFI 558-505 Ford Modular Valve Harness Kit can be a significant investment, depending on the specific engine and any additional components required for installation.

2. Learning Curve: While the installation process is generally straightforward, there is a learning curve associated with setting up and tuning the fuel injection system.

3. Requires Additional Components: In some cases, the kit may not include all the necessary components for a complete installation, such as a fuel pressure regulator or a wideband oxygen sensor.

If you're looking to upgrade your Ford Modular engine with electronic fuel injection, the Holley EFI 558-505 Ford Modular Valve Harness Kit is a solid choice. It offers improved fuel economy, better idle quality, easy installation, wide compatibility, and increased power. However, it comes with a higher cost and a learning curve for setup and tuning. Ultimately, the decision to purchase the kit depends on your specific needs, budget, and experience level.

If you're confident in your ability to install and tune the fuel injection system, and you're looking for a high-performance solution for your Ford Modular engine, then the Holley EFI 558-505 Ford Modular Valve Harness Kit is an excellent choice. However, if you're on a tighter budget or have limited experience with fuel injection systems, you may want to consider a less expensive alternative or seeking professional installation and tuning services.

part # 558505 price

• $1549.95

specifications injectiopug:

• for makes: Ford
• brand: Holley Efi
• part type: Valve Harness
• upc: 090127721377
• manufacturer part number: 558-505

returns injectiopug:

• time: 30 Days
• policy: Returns Accepted
• paid by: Seller

seller injectiopug:

• rating: 99.6%
• # reviews: 2008 7

offer injectiopug:

• availability: In Stock
• options: Ship-to-home
• quantity: 4
• sold: 0
• started: March 15, 2026

shipping injectiopug:

• class: Standard
• cost: $0.00
• type: Fixed
• carrier: UPS
• service: UPS Ground
• transit: 3-6 Days

payments injectiopug:

• wallet: Paypal
• credit card: Discover
• other

general injectiopug:

• condition: New
• Air Fuel Delivery > Fuel Injection Parts > Additional Fuel Injection Parts

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