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Holley Sniper EFI

Holley Super Sniper Stealth 4150 - 650HP - Gold Finish

4 Barrel Fuel Injection Conversion - Self-Tuning Kit + Handheld EFI Monitor - Gold Finish

Part # 550-875 Be the first to write a review
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The Sniper Stealth 4150 EFI system from Holley features 4, 100LB/HR Fuel Injectors capable of supporting up to 650 HP naturally aspirated or 600 HP on forced induction applications. The Sniper Stealth 4150 ECU is capable of fuel map self-learning and ignition timing control, improving idle stability, drivability, and wide-open throttle horsepower! Did we mention that the Stealth 4150 also includes transmission kick down provisions for GM TH350/400, 200R4/700R4 and Ford C4/C6 applications.


  • Bolt on 4150 flange carburetor replacement fit’s a wide range of factory intake manifolds
  • Throttle body mounted ECU (Electronic Control Unit) – no extra boxes to mount
  • Supports up to 650HP with four 100lb/hr injectors or 1250HP with eight 100lb/hr injectors
  • All of the wiring exits below the rear fuel injector cover, for a completely stealth installation
  • Timed spark part for vacuum advanced distributors located under the front fuel bowl, for easy access to the distributor
  • Three programmable 0-5V sensor inputs for oil/fuel/dome or nitrous pressure sensors
  • Six programmable ground outputs for controlling external fans, nitrous or boost control solenoids
  • One +5v reference output - +5V power supply for 0-5v sensors
  • One sensor ground – ground supply for 0-5v sensors
  • Air entry is machined to fit most stock style air cleaners with air cleaner locator provisions
  • Only 4 wiring connections required! (Battery +, battery - , switched ignition & RPM)
  • Requires use of external fuel pressure regulator, Holley PN# 12-886 or equivalent, set to a base pressure of 58.5 PSI
  • Integrated ignition timing control improves idle stability, drive-ability, and wide open throttle response
  • High resolution full color touchscreen for initial setup, tuning, and gauge displays
  • Simple calibration wizard (answer a few questions about your engine and it creates the base map, then starts tuning on its own!) - NO laptop required!
  • Self-tuning ECU means you don’t have to be a computer/tuning wiz to have EFI!
  • The included Genuine Bosch LSU 4.9 wideband oxygen sensor provides realtime fuel map learn!
  • OEM style TPS/IAC and fuel pressure regulator, for years of dependable service
  • Included clamp-on oxygen sensor kit for 2.25" exhaust ensures a leak free oxygen sensor installation, with stainless steel T-bolt clamps and a stainless steel (weldable) oxygen sensor flange
  • Also available in black and shiny
Brand Holley Sniper EFI
Emission Code3
FinishClassic Gold
Flange Style4150
Fuel Pressure58.5 PSI
Injector Size100 lb/hr @ 58.5 PSI
Inlet / Outlet Size3/4-16 Female O-Ring (AN 8)
MAP Sensor2Bar
Max Horsepower Rating650 Naturally Aspirated
Model4150 EFI Conversion Throttle Body
Product TypeSniper Stealth EFI
Ford C4/C6
Part Number550-875

This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles and Racing Use Only Vehicles.

The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles:

  • 1965 and older U.S. manufactured California Certified vehicles
  • 1967 and older U.S. manufactured Federally Certified vehicles
  • 1967 and older Foreign manufactured vehicle

The following vehicles are considered Racing Use Only Vehicles:

  • Racing Use Only Vehicles are vehicles that are used exclusively for competition and that are not registered and that may never be used on the street

WARNING: It is against the law to install this part on an Emissions Controlled Vehicle

The following vehicles are considered Emissions Controlled Vehicles:

  • 1966 and newer U.S. manufactured California Certified vehicles
  • 1968 and newer U.S. manufactured Federally Certified vehicles
  • 1968 and newer Foreign manufactured vehicle
Holley EFI Dealers
Do you need a custom kit built for your application? Do you need a system installed and tuned? Click here to find the Holley EFI dealer in your area!
Sniper EFI SD Card Contents
Sniper EFI SD Card Contents
Part # 534-247 is required to complete installation.

Have a question about this product?

  • Question

    What is the differnce between the Super Sniper Stealth and the Sniper Stealth?

    By Donald W. on February 7, 2020

    The Super ECU has extra Inputs and outputs, and an 8 injector variation for increased horsepower support on boosted applications.
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    *Free Shipping & Handling only offered to the contiguous US on orders over $100, excludes clearance parts and oversized packages.

    Some parts are not legal for use in California or other states with similar regulations.