SKU: 62516865524

HP EFI ECU & Harness Kits - 550-601

Sale price$1237.47 Regular price$1374.97
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Ships within 48 hours · Estimated delivery Jul 21 - Jul 26

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Description

HP EFI ECU & Harness Kits - 550-601Overview: Looking for a plug and play alternative for your stock or built late model factory EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along with

Overview:

Looking for a plug and play alternative for your stock or built late model factory EFI engine? How about a replacement ECU for your older Holley C950? Holley has you covered. HP EFI ECU and harness kits are designed to be used with popular factory EFI engines as an alternative to the factory ECU and harness or as a replacement for your C950 ECU. The HP allows you to accurately control the fuel and ignition of your engine along with additional controls for nitrous, boost, or water meth.

Features:

  • NEW V2 SOFTWARE FEATURES
  • “Quick Start” ignition and fueling strategy for LS x Engines
  • Data Logger. Scalable axes, Smoothing, Multiple graph view ability, Pre-defined notes fields and many more
  • Strip Chart Real-Time Data Viewer
  • Integrated Boost Control - Boost vs Time, Boost vs Gear (Time or RPM), Boost vs RPM, Boost vs Speed, Launch control. Boost launch builder, Over-boost safeties, Boost scramble
  • Traction Control - Power reduction via timing, nitrous percentage or boost (Requires Davis Technologies Holley Module)
  • “Quick Start” fueling for all engines
  • Option for VE based fueling strategy
  • Fuel Map and Learn Function Smoothing
  • Configurable User Password Protection
  • Fully Configurable lap top Gauge Panel
  • FEATURES
  • Optional 5.7” full-color touchscreen LCD allows easy on-the-fly tuning,data-logging or can be used as an easy to see graphical gauge panel
  • Eight sequentially driven 8:2 peak and hold injector drivers, capable of driving up to 16 low or high impedance injectors as a standard feature. Multiple staged injector strategies
  • Eight channel Distributorless Ignition (DIS)outputs capable of directly driving “Smart” ignition coils or Holley DIS coils. Will drive 2 wire coils with the addition of PN 554-112 high current coil driver module
  • Plug and Play control of factory GM 24x and 58x LSx engines
  • Integrated single channel wide band oxygen sensor control. Works with NTK or Bosch sensors
  • Internal data-logging standard with a huge 2GB of memory
  • 4 Stage progressive nitrous control
  • Turbo boost control
  • Integrated water/methanol injection control
  • Self-tuning fuel table strategy greatly simplifies tuning process
  • Individual cylinder fuel and spark control allows you to unlock your engine’s potential
  • Works with 4, 6, 8 cylinder engines
  • Unique lb/hr based fueling strategy greatly simplifies and commonizes tuning
  • Advanced idle, closed loop, and enrichment strategies allow for very stable operation
  • ECU is fully potted and can be mounted in the engine compartment or interior
  • Sealed automotive and marine grade connectors
  • Allows for use of common OEM sensors as well as customer sensor calibration input
  • Ignition Plug and Play with GM 24x and 58x LSx engines, GM HEI, Ford TFI, magnetic and hall effect trigger, and other ignition systems. New Plug and Play applications in process. Custom settings can be configured to allow many other applications
  • 1-5 Bar MAP sensor capability
  • Two channel knock control sensor Inputs for both one or two wire knock sensors
  • Dedicated fuel and oil pressure inputs
  • Controls both stepper and PWM Idle Air Control (IAC) motors
  • Speed density, Alpha-N, or combination fueling strategies
  • 4 Programmable high or low Pulse Width Modulated (PWM) outputs and 4 fully configurable inputs can be configured for use
  • 4 Stage nitrous oxide control
  • Fully featured nitrous control eliminates the need for a separate nitrous controller device
  • Can be configured “Wet” or “Dry” with closed loop feedback
  • Progressive control based on time, RPM, or boost, requires part # 554-111
  • Lean or rich safety cutoff
  • Full timing retard/control configurability per stage based on RPM or time
  • Integrated Water/Methanol injection control
  • Uses Holley Water/Meth solenoids specially designed and calibrated for use with this EFI system to allow the user to enter Water/Meth flow as a percentage of fuel injector flow for Water/Meth tuning precision unmatched in the industry

Application:

Year Make Model Submodel Engine Size
Universal

Specs:

Brand Holley EFI
Emission Code 3
Ignition Type Coil - (No Timing Control)
Ignition Type GM HEI Small Cap
Ignition Type Holley Dual Sync Distributor
Injector Connector Jetronic / Minitimer (Bosch)
Product Type HP EFI Kit
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 62516865524

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WVgal
Charlottesville, US
★★★★★ 5
Remarkable and impressive pillow
Size: Standard (Medium)
The pillow came quickly and was what was expected. After 6 months of chronic neck pain, one night on this pillow has made a world of difference. Please buy one of these if you are on the fence. They are wonderful. Highly recommend.
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Reviewed in the United States on April 14, 2026
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Mike Cena
Omaha, US
★★★★★ 3
Not any more breathable than other pillows
Size: Standard (Medium)
I got this in hopes that it would be cooler than other pillows but it seems to hold the same amount of heat. Additionally, as a side-sleeper, it is too thick for me. It is however pretty comfy and seems to be made out of quality material. As other reviews stated, it was smelly at first but that went away within a week.
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Reviewed in the United States on April 22, 2026
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Amazon Customer
Los Angeles, US
★★★★★ 5
Great pillow
Size: Standard (Medium)
I love latex pillows. They are bouncy but yet soft. This is my second one. This one is the medium and my first soft. I use soft on top laying watching tv and sleep with medium. No neck pain at all. I have always loved these from years ago. Will always use these only.
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Reviewed in the United States on January 16, 2026
B
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Britney
Massapequa, US
★★★★★ 1
Lost its firmness way too quick
Size: Standard (Medium)
I’ve used latex pillows almost my whole life & this has to be the worse one yet. These pillows usually last me years, I’ve only had this one about 4 months & it’s already gotten flat causing me neck pain. When I first got it I was skeptical since it was already very flat compared to what you get in store but I gave it a try anyway. I slept good for the first 2-3 months since the firmness was still there but now it’s not holding my neck up at all. On top of that the smell was stronger than usual and took about a month to go away. I’ve gotten cheaper latex pillows in store that have lasted me longer but I needed one fast so I decided to order this one.. Would not recommend.
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Reviewed in the United States on March 25, 2026
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Stephen
Chelsea, US
★★★★★ 5
EXCELLENT CHOICE
Size: Standard (High Loft), Number of Items: 1
ABSOLUTELY AWESOME ! I TRIED A MEDIUM SOFT PILLOW FROM ANOTHER COMPANY FOR $35 LESS, BUT IT COULDN'T STAND UP TO MY NEEDS OR EXPECTATIONS. THIS STANDARD SIZE PILLOW THAT IS "FIRM" AS OPPOSED TO SOFT OR MEDIUM, IS FANTASTIC FOR MY HEAD AND NECK. IT IS KEEPING MY CERVICAL SPINE ALIGNED WHILE I SLEEP AND RELIEVING THE HEADACHES THAT I HAVE BEEN HAVING DUE TO MY DEGENERATIVE DISC DISEASE IN MY NECK. GREAT PILLOW AND WELL WORTH THE EXTRA MONEY. THANK YOU !
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Reviewed in the United States on April 24, 2026

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