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- USA
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Ships within 48 hours · Estimated delivery Jul 10 - Jul 15
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For Your Every Summer RSVP, with Code: SUMMER15
Description
Holley 550-871K Holley Sniper EFI Stealth 4150 Master Kit - Black FinishOverview: 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 | Black |
| 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 ★★★★★
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Product Reviews
★★★★★ 5
Excellent Kindergarten prep
Format: Paperback
My daughter is loving all of the learning exercises and has started feeling more confident heading in to Kindergarten.
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Reviewed in the United States on May 20, 2026
★★★★★ 5
Excellent Summer Workbooks - Keeps Kids Engaged and Ready
Format: Paperback
These workbooks have been an absolute lifesaver for keeping my kids on track over the summer! I was looking for a resource that would help them retain what they learned and prepare for the next school year without feeling like a chore, and these deliver perfectly.
What I particularly love is how well **organized they are by days**. This structure eliminates any guesswork and makes it incredibly easy to assign manageable chunks of work each day, which helps to **keep my kids consistently on track**. There's no overwhelm, just steady progress.
The content is engaging, and it genuinely seems to reinforce key concepts in a fun way. We've had **absolutely no complaints** from the kids, which is a huge win for any summer learning material! I highly recommend these workbooks for any parent looking for a structured and effective way to bridge the academic gap during the summer break.
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Reviewed in the United States on May 28, 2025
★★★★★ 5
Fun for my Kindergarteners!
Format: Paperback
This activity book is a fantastic, age-appropriate resource that makes summer learning both fun and effective for Kindergarteners transitioning to 1st grade! The pages are thoughtfully designed with easy-to-follow activities that keep young minds engaged while reinforcing essential skills. The addition of flashcards, stickers, and eBooks takes the learning experience to the next level, making practice feel like playtime.
One of my favorite features is the encouragement of hands-on learning and movement through exciting fitness challenges—because learning shouldn't just be about worksheets! It turns what could be a boring review into an adventure filled with creativity and energy. This workbook truly helps bridge the summer gap while keeping kids motivated and excited for the next school year. A must-have for any little learner’s summer routine!
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Reviewed in the United States on March 19, 2025
★★★★★ 5
Recommend
Format: Paperback
Has been a great learning book
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Reviewed in the United States on February 11, 2026
★★★★★ 4
Teacher approved
Format: Paperback
Great review book to help bridge the learning between Kindergarten and 1st grade. Teacher approved!
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Reviewed in the United States on May 25, 2025