SKU: 81238612722

Holley Sniper EFI 4BBL Self Tuning System with PDM,Black (HO550-511-3PX)

Sale price$1615.05 Regular price$1794.50
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Description

Holley Sniper EFI 4BBL Self Tuning System with PDM,Black (HO550-511-3PX)HO550 511 3PX HOLLEY SNIPER 2 EFI BLACK 800 cfm 4 Injector Throttle Body, 650 HP N A Part Number: HO550 511 3PX The #1 EFI conversion system just got better! Introducing Sniper 2 EFI a self tuning, easy to install, EFI conversion for common 4 barrel (4150 flange) style carburetors. We took everything that we learned from the original Sniper EFI system and added 14 new features that will make your EFI conversion more simple, reliable, and modern. Like

HO550-511-3PX - HOLLEY SNIPER 2 EFI BLACK

800 cfm 4 Injector Throttle Body, 650 HP N/A

Part Number: HO550-511-3PX

The #1 EFI conversion system just got better! Introducing Sniper 2 EFI - a self-tuning, easy-to-install, EFI conversion for common 4-barrel (4150 flange) style carburetors. We took everything that we learned from the original Sniper EFI system and added 14 new features that will make your EFI conversion more simple, reliable, and modern. Like all Sniper EFI systems, Sniper 2 is designed to work with the Sniper Ecosystem that includes Hyperspark ignition, complete fuel systems, multiple user interfaces/dash displays, and more.
New for Sniper 2 is the optional Power Distribution Module (PDM). This cost-effective and optional accessory isolates the core of your EFI and ignition wiring into one, easy-to-use location. Simply slide the stripped wire ends under the positive lock connector and tighten down the set screw. Battery and a switched 12-volt source is all that's required from your vehicle to power the PDM and your Sniper EFI.
Make your classic drive like a modern fuel-injected vehicle, including easy cold starts, smooth drivability, and improved fuel economy! Sniper 2 is designed to be installed at home in your garage with limited tools and the support of Holley's comprehensive installation manual and videos. The user-friendly setup wizard allows you to answer a few simple questions about your engine and the system will begin self-tuning with no laptop or tuning experience required.
If you're looking for a high-performance fuel injection system that delivers power, efficiency, and ease of use, look no further than the Sniper 2 EFI.
Main Features
All new design – the #1 EFI Conversion just got better!
Only four wiring connections required: Battery+, Battery-, Switched Ignition, and RPM
Calibration wizard only requires that you answer a few simple questions about your engine to create a base map and begin self-tuning – No laptop required
Supports up to 650hp naturally aspirated or 575hp on boost with four 100 lb/hr injectors
NEW Next generation ECU features improved RF noise and interference resistance (stands up to old car wiring, noisy alternators, faulty plug wires)
NEW Redesigned throttle shaft and plate geometry for a smoother throttle feel

Sniper 2 is Part of the Sniper EFI Complete Ecosystem

Sniper 2 is compatible with the complete Sniper EFI Ecosystem that includes plug-n-play Hyperspark Ignition systems (coil, ignition box and distributor), fuel systems (fuel lines, fuel pump hangers), multiple displays and more
NEW Main harness includes plug-and-play HyperSpark distributor support, for integrated timing control, making your ignition setup hassle free
NEW Adaptors for other ignition types sold separately: 558-329 CD Box to Sniper 2, 558-330 MSD Pro Billet / Crank Trigger to Sniper 2
NEW Wide Variety of tuning and gauge display interfaces: from a 3.5-inch full color LCD Handheld, 5-inch Digital Dash, or the Bluetooth dongle, which allows you to connect either an iOS or Android based cell phone to your Sniper 2
NEW Optional Power Distribution Module (PDM) further simplifies wiring, especially when used in conjunction with an ignition system
Available with fuel system kits: a complete fuel system consisting of: 20 ft. of 3/8 in. Vapor Guard Fuel Hose, Fuel Pump, fuel pressure regulator, filters, necessary hardware, and bulkhead fitting to return fuel into the tank

Additional Features
NEW Integrated transmission kick down provisions for GM TH350/400, 200-4R/700R4 and Ford C4/C6 applications
NEW "Hidden Harness" wiring harnesses exits from the rear of throttle body for a clean appearance
NEW Inputs and outputs consist of: 2x Ground Inputs, 2x Ground Outputs, 1x TPS output (0-5v), and 1x Tach Output
NEW Redesigned injector connector for improved reliability
NEW Onboard contactless magnetic TPS sensor e

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
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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]
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SKU: 81238612722

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kbellco
Lake Worth, US
★★★★★ 5
Great little notebook
Style: COVER
I love these little notebooks. I have a case that they fit in just fine, along with a pencil. I use them primarily for my ham radio hobby for when I go to a park and need to record the contacts that I have made for the log.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 19, 2026
J
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Jaden T Wilson
Port Orchard, US
★★★★★ 5
Solid
Style: KIT
Waterproof, great for field exercises
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 9, 2026
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teddy
Charlottesville, US
★★★★★ 4
Nice quality but could be better for the price.
Style: COVER
So nice quality but strange dimensions. There is no way to fold a standard 8.5x11" sheet of computer paper to fit neatly in this. So if you want to print out your own documents to take with you in this, this isn't ideal. Has 2 internal pen slots and one on the outside. Has two business card slots but I wish it had more.
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Reviewed in the United States on January 21, 2026
R
Verified Purchase
Runner Chick
Massapequa, US
★★★★★ 5
Pen Holder is Very Narrow
Style: COVER
Overall this item is effective for holding a Rite in the Rain 4.625" x 7" spiral side-bound notebook. There is no zipper on this so it does not seal. It has slots for a few cards and folded or smaller items can be tucked behind the notebook in the pockets that hold the covers. I haven't used it in the rain enough yet to know if those papers I have tucked in will stay dry. The description says a cell phone could be stored in those pockets as well. I haven't tried this, but my cell phone with a cover wouldn't fit. If you have a thin cell phone it might work, but I prefer to put both covers slid into the pockets so the notebook stays open easier when using it. The outer elastic closure is tight enough without being too tight. However, the pen holders are quite tight and small. They likely work well to hold in the Rite in the Rain pen that is narrow and smooth and possibly a narrow and smooth mechanical pencil, but they are too tight for my side click mechanical pencil. I could barely slide it in and when I tried to pull it out, the top half pulled off the bottom half of the pencil. It would also be a struggle to put larger pens in and out, but the elastic might stretch to fit those that are smooth over time. Despite not being able to use the loops for my preferred pencil, I chose to keep it.
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Reviewed in the United States on November 23, 2025
M
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MAK
Fort Morgan, US
★★★★★ 5
Just what I was wanting
Style: KIT
Ordered to use a a gym notebook to track my progress. It’s holding up well being exposed to being shoved in a cramped gym bag repeatedly over the last 2 months. Sweat and water hasn’t hurt it and the cover seems to be holding up well. Still looks practically brand new.
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Reviewed in the United States on November 5, 2025

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