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    Sale!

    Holley EFI Ford 2V & 4V Modular Main Harness, For HP EFI & Dominator EFI | 558-108

    Vendor: Holley EFI
    Part Number: 558-108
    Save $107
    Sale Price $849.95 Regular Price $956.95

    In Stock

    Not sure it fits your vehicle?
    Email sales@berryperformancesales.com with your year, make, model and engine, and we'll help you check fitment before you order.
    Fast Fulfillment: In-stock orders typically ship within 1 to 2 business days.
    Free Shipping on Orders Over $99 | Excludes freight shipments
    International Shipping Available: email sales@berryperformancesales.com for a quote.
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    This main harness fits 1999-2004 Ford 2-valve and 4-valve Modular 4.6L and 5.4L engines and is designed for use with Holley's HP EFI and Dominator EFI systems.

    Specifications:

    • Application: 1999-2004 Ford Modular 4.6L & 5.4L, 2V and 4V
    • Harness Application: Ford
    • Harness Type: Main
    • Compatible ECUs: HP EFI, Dominator EFI
    • Part Number: 558-108

    Compliance: This part is legal for sale and use on Racing Use Only Vehicles — competition vehicles that are not registered and never operated on the street. It is against the law to install this part on an Emissions Controlled Vehicle (1966-and-newer California-certified or 1968-and-newer federally certified vehicles).

    FAQ

    What Ford engines does this main harness fit?

    It fits 1999-2004 Ford Modular 4.6L and 5.4L engines, both 2-valve and 4-valve.

    Which Holley EFI systems is this harness designed for?

    It's built for use with Holley's HP EFI and Dominator EFI systems.

    Is this harness legal for street use?

    No. This part is for Racing Use Only Vehicles and is not legal to install on an emissions-controlled street vehicle.

    What part number is this harness?

    This Ford 2V & 4V Modular main harness is Holley part number 558-108.

    Shipping Policy
    • Free shipping on orders over $99 (excludes freight shipments).
    • In-stock orders typically ship within 1 to 2 business days. Weekend and holiday orders are processed the next business day.
    • Orders ship from Defiance, Ohio and a nationwide network of warehouses and manufacturers.
    • Items showing an ETA are not in stock yet. ETAs come from the manufacturer and can change.
    • No P.O. Boxes. International orders need a shipping quote, so email us first.

    Read the full Shipping Policy

    Return Policy
    • 30-day return window from the ship date. Returns must be approved first; email sales@berryperformancesales.com with your order number.
    • Items must be unused, complete and in the original packaging.
    • A 20% restocking fee applies, and return shipping is paid by the buyer.
    • Not returnable: installed or modified parts, opened or used programmers and tuners, custom orders, Open Box, and Clearance or Final Sale items.
    • Damaged, defective or incorrect items must be reported within 48 hours of delivery with photos.

    Read the full Return Policy

    Disclaimer

    All products are sold for off-road use only unless otherwise specified. Buyer assumes all responsibility for installation and operation. Seller is not liable for any incidental, indirect, or consequential damages — including engine failure, labor costs, or vehicle downtime — resulting from the use of any product sold.

    By making a purchase from Berry Performance Sales, you acknowledge and agree to abide by the terms and conditions of these Policies.

    For any questions or concerns, please contact us — we’re always happy to help.

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