

Holley EFI 550-870K 4150 Sniper Stealth Master Kit
Key item features
- Direct Replacement: This system offers a bolt-on 4150 flange carburetor replacement, integrating a "brain box" directly onto the throttle body for a clean installation.
- Powerful Performance: Supports up to 650 horsepower with four 100 Lb/Hr injectors for naturally aspirated engines, or 600 HP for forced induction applications.
- Stealthy Wiring: All wiring exits discreetly below the rear fuel injector cover, ensuring a completely stealthy installation.
- Simplified Setup: Requires only four wiring connections (Battery +, Battery -, Switched Ignition & RPM) and includes a high-resolution full-color touchscreen for initial setup and gauge displays.
- Self-Tuning Capability: Features a simple calibration wizard and a self-tuning brain box, utilizing a Genuine Bosch LSU 4.9 Wideband Oxygen Sensor for real-time fuel map learning.
- Comprehensive Kit: Master Kits include a complete fuel system with an external fuel pressure regulator preset to 58.5psi, 20ft of 3/8" Vapor Guard Fuel Hose, fuel pump, filters, and necessary hardware.
Specs
- Vehicle model550-870K
- Vehicle makeFord
- Vehicle fitment typeUniversal
- Automotive parts divisionPerformance
- BrandHolley Sniper EFI
- FeaturesHandheld
- Free shipping
Free 90-day returns
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| Product | Viewing this itemHolley EFI 550-870K 4150 Sniper Stealth Master Kit ![]() $1,799.95 current price $1,799.9544.8 out of 5 Stars. 4 reviews | Holley 550-511-BPX-SBF Sniper 2 EFI Bundle w/ Hyperspark Ignition System - Fits Ford ![]() $1,999.95 current price $1,999.95 | Holley Sniper EFI 19-478 Sniper EFI Fuel Tank System 400 LPH ![]() $1,024.95 current price $1,024.95 | Holley Sniper EFI 550-872K Holley Sniper Stealth 4150 Master Kit - Gold Finish ![]() $1,849.95 current price $1,849.95 | Holley Sniper 2 EFI Bundle Kit SBC BLACK ![]() $1,949.95 current price $1,949.95 | Holley Sniper EFI 556-154 HyperSpark 2 CD Ignition Box ![]() $399.95 current price $399.95 | Holley EFI 550-871 4150 Sniper Stealth ![]() $1,536.39 current price $1,536.39 | Holley Sniper EFI 565-305K HyperSpark Distributor Master Kit ![]() $1,024.95 current price $1,024.95 | Holley EFI 550-857K Sniper EFI 2GC Large Bore Master Kit ![]() $1,599.95 current price $1,599.95 |
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| Vehicle model | 550-870KHolley EFI 550-870K 4150 Sniper Stealth Master Kit | 550-511-BPX-SBFHolley 550-511-BPX-SBF Sniper 2 EFI Bundle w/ Hyperspark Ignition System - Fits Ford | Blazer / Jimmy / SuburbanHolley Sniper EFI 19-478 Sniper EFI Fuel Tank System 400 LPH | -Holley Sniper EFI 550-872K Holley Sniper Stealth 4150 Master Kit - Gold Finish | 550-511-BPX-SBCHolley Sniper 2 EFI Bundle Kit SBC BLACK | SNP556-154Holley Sniper EFI 556-154 HyperSpark 2 CD Ignition Box | -Holley EFI 550-871 4150 Sniper Stealth | -Holley Sniper EFI 565-305K HyperSpark Distributor Master Kit | -Holley EFI 550-857K Sniper EFI 2GC Large Bore Master Kit |
|---|---|---|---|---|---|---|---|---|---|
| Vehicle make | FordHolley EFI 550-870K 4150 Sniper Stealth Master Kit | FordHolley 550-511-BPX-SBF Sniper 2 EFI Bundle w/ Hyperspark Ignition System - Fits Ford | ChevroletHolley Sniper EFI 19-478 Sniper EFI Fuel Tank System 400 LPH | -Holley Sniper EFI 550-872K Holley Sniper Stealth 4150 Master Kit - Gold Finish | ChevyHolley Sniper 2 EFI Bundle Kit SBC BLACK | -Holley Sniper EFI 556-154 HyperSpark 2 CD Ignition Box | FordHolley EFI 550-871 4150 Sniper Stealth | ChryslerHolley Sniper EFI 565-305K HyperSpark Distributor Master Kit | ChevroletHolley EFI 550-857K Sniper EFI 2GC Large Bore Master Kit |
| Vehicle fitment type | UniversalHolley EFI 550-870K 4150 Sniper Stealth Master Kit | SpecificHolley 550-511-BPX-SBF Sniper 2 EFI Bundle w/ Hyperspark Ignition System - Fits Ford | SpecificHolley Sniper EFI 19-478 Sniper EFI Fuel Tank System 400 LPH | SpecificHolley Sniper EFI 550-872K Holley Sniper Stealth 4150 Master Kit - Gold Finish | SpecificHolley Sniper 2 EFI Bundle Kit SBC BLACK | SpecificHolley Sniper EFI 556-154 HyperSpark 2 CD Ignition Box | UniversalHolley EFI 550-871 4150 Sniper Stealth | SpecificHolley Sniper EFI 565-305K HyperSpark Distributor Master Kit | SpecificHolley EFI 550-857K Sniper EFI 2GC Large Bore Master Kit |
| Automotive parts division | PerformanceHolley EFI 550-870K 4150 Sniper Stealth Master Kit | PerformanceHolley 550-511-BPX-SBF Sniper 2 EFI Bundle w/ Hyperspark Ignition System - Fits Ford | PerformanceHolley Sniper EFI 19-478 Sniper EFI Fuel Tank System 400 LPH | PerformanceHolley Sniper EFI 550-872K Holley Sniper Stealth 4150 Master Kit - Gold Finish | PerformanceHolley Sniper 2 EFI Bundle Kit SBC BLACK | -Holley Sniper EFI 556-154 HyperSpark 2 CD Ignition Box | PerformanceHolley EFI 550-871 4150 Sniper Stealth | PerformanceHolley Sniper EFI 565-305K HyperSpark Distributor Master Kit | PerformanceHolley EFI 550-857K Sniper EFI 2GC Large Bore Master Kit |
About this item
Product details
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 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.
Master Kits include complete fuel system with an external fuel pressure regulator preset to 58.5psi, 20ft of 3/8" Vapor Guard Fuel Hose, Fuel Pump, Filters, necessary hardware and bulkhead fitting to return fuel into the tank!;
- Bolt on 4150 Flange Carburetor Replacement
- Throttle body mounted "brain box", no extra boxes to mount
- Supports up to 650hp with Four 100 Lb/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.
- 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)
- External fuel pressure regulator required, set to a base pressure of 58.5 PSI, such as 12-886.
- Integrated ignition timing control
- High Resolution Full Color Touchscreen for Initial Setup 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 brain box means you don't have to be a computer wiz to have EFI!
- The included Genuine Bosch LSU 4.9 Wideband Oxygen Sensor provides real-time 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
- vailable in 3 finishes: Shiny, Black and coming soon, Gold
Specifications
Vehicle model
Vehicle make
Vehicle fitment type
Automotive parts division
Warranty
Warranty information
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Customer ratings & reviews
Filtered and sorted results would be available on the new 'Customer ratings & reviews' page.
Showing 1-3 of 3 reviews
Work great
I decided to try this Sniper System to help eliminate tuning a carb on new engine I installed in my Chevelle. I recommend you watch the install video a couple of times The manual is a on line PDF file and try to understand it all before installing. After reading and watching it is a easy operation. The wires are easy enough and I used a in tank fuel pump kit for my instal I chose that over drilling a hole in fuel tank for a fuel return line. Now I just drive and watch it tune itself. So far so good!!!!
Easy install
Installed in 2 days with fuel system and hyperspark. Awesome and easy to use!
Works great
System is great and easy to install the only problem is the kit is not complete it doesn’t come with the two into one fuel line you have to order it separate part # Holley 34-42 and it $124.00 which is no big deal but it says this is a master kit which should include everything. It cost me about two days wait time but I’m very pleased with it
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