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Ships within 48 hours · Estimated delivery Jul 11 - Jul 16
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Description
Holley 550-870K Sniper Stealth 4150 Self-Tuning Fuel Injection System Master KitOverview: 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
Overview:
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. Part # 34-42 is required for a bolt-in installation.
Features:
- Bolt on 4150 Flange Carburetor Replacement
- Throttle body mounted ECU - 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, 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 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
- Available in 3 finishes: Shiny, Black and coming soon, Gold
Application:
| Year | Make | Model | Submodel | Engine Size |
|---|---|---|---|---|
| Universal |
Specs:
| Brand | Holley Sniper EFI |
|---|---|
| CFM | 870 |
| Emission Code | 3 |
| Finish | Shiny |
| Flange Style | 4150 |
| Fuel Pressure | 58.5 PSI |
| Height | 3.28" |
| Injector Size | 100 lb/hr @ 58.5 PSI |
| Inlet / Outlet Size | 3/4-16 Female O-Ring (AN 8) |
| MAP Sensor | 2Bar |
| Max Horsepower Rating | 650 Naturally Aspirated |
| Model | 4150 EFI Conversion Throttle Body |
| Product Type | Sniper Stealth EFI |
| Transmission | 700R4/200R4 |
| Transmission | Ford C4/C6 |
| Transmission | TH350 |
| Warning | California Proposition 65 |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- 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
4.2 ★★★★★
Based on 1244 reviews
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Product Reviews
★★★★★ 5
Excellent !!
Size: Standard (Pack of 2), Color: Original White
Like many other folks my age, I suffer with Neck & Shoulder pain throughout the night. I have bought and tried several Gel-Foam Bed Pillows, even the contoured pillows. None of these pillows can compare to the Vaverto Memory Form Pillows !! These Vaverto's Pillows are the Best Supported and Comfort Gel-Infused Pillows I have ever slept on !! They have just the right amount of firmness for good neck support. I Highly Recommended These "Vaverto Memory Foam Pillows" For Neck Pain Relief And A Good Nights Sleep !! JimA, Mt.Vernon, Mo.
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Reviewed in the United States on April 27, 2026
★★★★★ 5
Nice Pillows!
Size: King (Pack of 2), Color: Original White
Very nice, quality pillows. They came compressed but expanded very quickly when the plastic wrapping was removed. They are a bit firm but are very comfortable and soft. Very pleased with the pillows.
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Reviewed in the United States on May 1, 2026
★★★★★ 5
Great pillow
Size: King (Pack of 2), Color: Original White
Extremely satisfied. Comfortable. Soft but maintains support of my head and neck. Well made. High quality. Highly recommend.
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Reviewed in the United States on May 16, 2026
★★★★★ 4
Comfortable, cool and doesn't go flat.
Size: Standard (Pack of 1), Color: Original White
Great pillow. It stays cooler than most and it doens't go flat. The memory foam is firm enough that your head doesn't sink into it but soft enough for a good night sleep. Before I was fluffing and flipping my pillow all the time to get the cool spots and not feel like it was flat. This is my 2nd purchase, my son liked mine so much that I got him one too. It's good value for the price and I would definitely recommend it.
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Reviewed in the United States on February 23, 2026
★★★★★ 5
Firm for the Win- A pillow that provides support and value!
Size: Standard (Pack of 1), Color: Original White
If you are a firm pillow kind of person... and don't want to spend hundreds on a name brand pillow, then this one is a clear winner! Ideal for back and side sleepers, this pillow seems to adjust to your body over time- becoming more comfortable with more nights spent with it (kind of like a hotel pillow- the first night you're not sure, then you sleep like a baby when you get used to it!).
My husband—an avid memory foam pillow fan—was pleasantly surprised. It took a night or two to adjust, but once he did, this cool pillow’s contours supported his neck beautifully whether he was on his back or side (especially when I nudged him to stop snoring!).
This pillow seems best suited for folks who need a bit more elevation—those with broader shoulders or who prefer higher neck support. It feels solid and delivers the firm support many sleepers crave.
If you lean toward soft, squishy down pillows, this may not be your match. It’s ultra-firm and structured, not plush or compressible. But if firm is your jam, this pillow punches above its price point.
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Reviewed in the United States on November 3, 2025