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Holley Terminator X Stealth 4150 EFI Fuel Injection Systems 550-1003 Systems, X, EFI, Four Injectors, Throttle Body, Speed Density, Aluminum, Gold, Tunable, Kit

SKU: HLY550-1003

Fuel Injection Systems

Holley Terminator X Stealth 4150 EFI Fuel Injection Systems 550-1003 Systems, X, EFI, Four Injectors, Throttle Body, Speed Density, Aluminum, Gold, Tunable, Kit

SKU: HLY550-1003

Fuel Injection Systems
A$4,349.21
IN STOCK! Est Ship 4-7 days. In stock at 2 locations (7 available)

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Description

Fuel Injection - Terminator X Stealth - Throttle Body - Square Bore - Aluminum - Gold - GM LS-Series - Kit


Data: v2 - Desc: v4.2 - Upd: 2026-11-08 02:16:28

Data: v4.2 - Upd: 2026-11-08 06:32:45

Features

Vehicle Compatibility and Return Conditions.

This item was designed and engineered in the USA for US domestic vehicles. OBD tools, ECUs, dongles, programmers, and tuners may have limited compatibility with vehicles outside the USA due to regional differences in emission standards and system configurations. Some features and functionality may vary depending on the vehicle and location.

Some electronic tuning devices and programmers require activation, registration, or pairing with a specific vehicle’s VIN (Vehicle Identification Number). Once activated or paired, these devices may become permanently associated with that vehicle, restricting or preventing their use on another vehicle, resticting our ability to offer returns or exchanges.

Please review the product details and images to ensure it meets your needs. For clarification or assistance, feel free to contact a StreetFX agent. Note: Returns are not accepted for special order or tuning products unless the unit is deemed faulty.

(keyword: efi)

Images are supplied by the manufacturer and may be generic. While all efforts are made to provide accurate pictures, there may be differences in the actual product, such as colour, quantity, version, or included components. Please carefully review the description and specifications for details on inclusions or any variations. Some items may be sold individually or in sets, and images may occasionally depict additional products or quantities not included in your purchase. For assistance or clarification, please contact customer support.

Specifications

Reference Information

Reference Data (Provide these details to our support team)
Brand Name/s Holley, Hilborn, Holley Efi, Retrobright, Terminator X
StreetFX SKU hly550-1003
SFX Item ID 4783566
Accounting SKU hly-550-1003
Manufacturer SKU 550-1003
Manufacturer UPC 090127093580
Alternative References 550-1003, HLY-550-1003, HOL550-1003

Fuel Injection Systems, Terminator X, Stealth 4150 EFI, Four Injectors, Throttle Body, Speed Density, Aluminum, Gold, Tunable, Kit

Holley Terminator X Stealth 4150 EFI systems feature 4 or 8, 100 lb. fuel injectors capable of supporting up to 650 hp naturally aspirated, and 600 or 1250 hp on forced induction applications. The Terminator X ECU is capable of fuel map self-learning and ignition timing control, improving idle stability, drivability, and wide-open throttle horsepower! The throttle body has the standard 4150 carburetor flange so it will bolt down where your square bore carburetor was. Holley Terminator X Stealth 4150 systems also include transmission kick-down provisions for GM TH350, TH400, 200R4, 700R4, and Ford's C4 and C6 applications!

Product Attributes
BrandHolley
Manufacturer's Part Number550-1003
Part TypeFuel Injection Systems
Product LineHolley Terminator X Stealth 4150 EFI Fuel Injection Systems
UPC090127093580
Fuel Injection StyleThrottle body
Fuel Injection System TypeSingle 4-Barrel Throttle Body (4150 Flange)
Maximum Horsepower with Gas650
Timing Control CompatibleYes
ECM IncludedYes
Self TuningYes
User TunableYes
Fuel System IncludedNone
Ignition System IncludedNone
Power Distribution IncludedNone
User Interface Included3.5 in. display
EGRNo
Transmission Controller IncludedNo
Metering StyleSpeed density
Multi-Port Fuel Rails IncludedNo
Throttle Body IncludedYes
Throttle Body Mounting Flange4-barrel square bore
Venturi Quantity4
Venturi Diameter (mm)44.45mm
Airflow Rate (cfm)950 cfm
Throttle Body MaterialCast aluminum
Throttle Body ColorGold
Injectors IncludedYes
Injector Size (lbs/hr)100 lbs./hr.
Calibration Module IncludedYes
Wiring Harness IncludedYes
Oxygen Sensor IncludedYes
Fuel Pressure Regulator IncludedNo
MAP Sensor IncludedYes
IAT Sensor IncludedYes
TPS Sensor IncludedYes
IAC Motor IncludedYes
QuantitySold as a kit.
NotesExternal fuel pressure regulator required, set to a base pressure of 58.5 psi.
Special AttentionNot for use with dual carburetor setups.

Compatibility

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