The Holley Sniper Stealth 4150 Master Kit gives a traditional carburetor look while functioning as a complete self-tuning EFI system, converting a 4150-flange engine to electronic fuel injection with just four wiring connections. The kit supports up to 650 hp naturally aspirated (600 hp boosted) using four 100 lb/hr injectors, and pairs a built-in calibration wizard with a high-resolution 3.5" full-color touchscreen so no laptop or outside tuning expertise is required. A complete return-style fuel system, Genuine Bosch LSU 4.9 wideband oxygen sensor, OEM-style TPS/IAC, fuel pressure regulator, stainless steel T-bolt clamps, and a stainless steel weldable oxygen sensor flange are all included, and transmission kickdown provisions are built in for GM TH350/400, 200R4/700R4, and Ford C4/C6 applications.
Key Features:
- Integrated ignition timing control improves idle stability, drivability, and wide-open-throttle response
- Genuine Bosch LSU 4.9 wideband oxygen sensor provides real-time fuel map learning
- Requires an external fuel pressure regulator (Holley 12-886 or equivalent) set to a base pressure of 58.5 PSI
- All wiring exits below the rear fuel injector cover for a completely stealth installation
- Bolt-on 4150-flange carburetor replacement fits a wide range of factory intake manifolds
- Only 4 wiring connections required (battery+, battery-, switched ignition, RPM)
- High-resolution full-color touchscreen for initial setup, tuning, and gauge displays
- Timed spark output for vacuum-advance distributors located under the front fuel bowl for easy access
- Self-tuning ECU with a simple calibration wizard — no laptop required
- OEM-style TPS/IAC and fuel pressure regulator for years of dependable service
- Air entry is machined to fit most stock-style air cleaners with air cleaner locator provisions
- Includes a clamp-on oxygen sensor kit for 2.25" exhaust with stainless steel T-bolt clamps and a weldable stainless steel oxygen sensor flange
- Throttle body-mounted ECU — no extra boxes to mount
Specifications:
- Flange Style: 4150
- CFM: 870
- Max Horsepower Rating: 650 (naturally aspirated)
- Injector Size: 100 lb/hr @ 58.5 PSI
- Fuel Pressure: 58.5 PSI
- Fuel Pump Flow Rating: 240 LPH
- MAP Sensor: 2 Bar
- Inlet/Outlet Size: 3/4-16 Female O-Ring (AN 8)
- Transmission Compatibility: 700R4/200R4, Ford C4/C6, TH350
- Finish: Classic Gold
- Height: 3.28"
- Part Number: 550-872K
Holley part # 534-247 is required to complete installation, and part # 34-42 is required for a bolt-in installation. This kit is also available in Black (550-871) and Shiny (550-870) finishes.
FAQ
What horsepower can the Sniper Stealth 4150 Master Kit support?
It supports up to 650 hp naturally aspirated and 600 hp boosted, using the included four 100 lb/hr injectors.
Do I need a laptop to tune this system?
No. A built-in calibration wizard walks through a few questions about the engine and begins self-tuning automatically, using the 3.5" full-color touchscreen for setup and gauge display.
What additional parts are required for installation?
Holley part # 534-247 is required to complete installation, and part # 34-42 is required for a bolt-in installation. An external fuel pressure regulator (Holley 12-886 or equivalent) set to 58.5 PSI is also required.
What transmissions does the kickdown provision support?
The Stealth 4150 includes transmission kickdown provisions for GM TH350/400, 200R4/700R4, and Ford C4/C6 applications.
What other finishes are available for this kit?
The same kit is also available in Black (Holley 550-871) and Shiny (Holley 550-870) finishes.