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Ignitions and Electrical Computers, Chips, Modules and Programmers

Holley

MPFI HP ECU AND HARNESS KIT

$2,936.95 $2,609.95 Save $327.00

SKU: H00E 550-604

In Stock
In Stock
Ships by Jun 7
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Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Description

The Holley 550-604 HP EFI ECU & Harness Kit is a powerful, self-tuning system designed to simplify the conversion of carbureted engines to electronic fuel injection (EFI). This kit is ideal for a wide range of applications, including street performance, mild race, and marine. It provides precise fuel control for optimal performance and efficiency, adapting to various engine modifications.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandHolley
Part NumberH00E 550-604
Weight9.05 lb

Videos

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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