--- product_id: 39352531 title: "Holley 550510 Electronic Fuel Injection" brand: "holley" price: "Β£1167.01" currency: GBP in_stock: true reviews_count: 9 url: https://www.desertcart.co.uk/products/39352531-holley-550510-electronic-fuel-injection store_origin: GB region: United Kingdom --- # Self-Tuning ECU Supports 650hp Dual Pattern Design Holley 550510 Electronic Fuel Injection **Brand:** holley **Price:** Β£1167.01 **Availability:** βœ… In Stock ## Summary > πŸš€ Elevate Your Ride with Effortless Power! ## Quick Answers - **What is this?** Holley 550510 Electronic Fuel Injection by holley - **How much does it cost?** Β£1167.01 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.co.uk](https://www.desertcart.co.uk/products/39352531-holley-550510-electronic-fuel-injection) ## Best For - holley enthusiasts ## Why This Product - Trusted holley brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - β€’ **Marine Ready:** Flame arrestor required for safe marine installations. - β€’ **User-Friendly Setup:** Only 4 wiring connections needed for quick installation. - β€’ **Powerful Performance:** Supports up to 650hp with four 100 Lb/Hr injectors. - β€’ **Seamless Integration:** Bolt-on replacement for 4150 Flange & Spread Bore manifolds. - β€’ **Smart Tuning Technology:** Self-tuning ECU eliminates the need for complex computer setups. ## Overview The Holley 550510 Electronic Fuel Injection is a cutting-edge dual pattern carburetor replacement designed for seamless integration with 4150 Flange & Spread Bore manifolds. It features a self-tuning ECU that simplifies installation and tuning, supporting up to 650hp with minimal wiring. Ideal for both automotive and marine applications, this product ensures high performance without the hassle of complex setups. ## Description Holley just brought EFI within range! Introducing Sniper EFI! It's economically priced so you can have all the benefits of EFI and still have money to finish or upgrade the rest of your ride! Perfect for street rods, muscle cars, off road trucks or nearly any carbureted vehicle. Put an end to cold start issues, hesitations, vapor lock, and flooding. Upgrade to Sniper EFI and get the tactical accuracy of EFI today ## Features - Dual Pattern bolt on carburetor replacement, designed to fit 4150 Flange & Spread Bore manifolds - (Spread Bore Sealing Plate Part #9006 is recommended) - Throttle body mounted ECU – no extra boxes to mount. Supports up to 650hp with Four 100 Lb/Hr Injectors! - Only 4 Wiring Connections Required! (Battery +, Battery - , Switched Ignition & RPM). A Flame Arrestor is REQUIRED for marine installations, such as part number, 720-1 or 720-13 - Self-tuning ECU means you don't have to be a computer/tuning wiz to have EFI!. 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! Note : Refer to the PDF attached below in Technical Specification for User Manual ## Images ![Holley 550510 Electronic Fuel Injection - Image 1](https://m.media-amazon.com/images/I/71dqp8SRTxL.jpg) ## Customer Reviews ### ⭐⭐⭐⭐ Runs fantastic and no more gas smell *by L***N on Reviewed in the United States πŸ‡ΊπŸ‡Έ on September 16, 2018* I installed the Holley Sniper EFI and the Holley Sniper Fuel tank on my 1971 440 Cuda mainly to get rid of the gas smell from my car. The carb ran good but after driving the car you and the house smelled like an old gas station. I followed the Sniper installation video exactly and to my surprise she fired right up and ran perfectly right out of the box. I drove around to let it self tune and can't be happier with the way the Sniper performs. No more cold start problems, no gas smell, better gas mileage and more horsepower. The only tricky part was finding a 12V source during cranking and run. Old Mopar's don't have a single source for that so I had to come off two sources and run thru a diode. The only negative I have on the Sniper EFI system so far is that my EFI monitor will automatically switch to a different screen after driving for a while. I'm not sure if this is by design or some issue with my system. If it weren't for this issue I would have given it 5 stars ### ⭐⭐⭐ holley fixed the issue and got me what I needed - Then broke again *by S***E on Reviewed in the United States πŸ‡ΊπŸ‡Έ on May 1, 2017* I'll give it 3 stars for now as it is installed on my vehicle but I can't turn my vehicle on yet because I am missing 2 important wiring harnesses that never came in the box. I am missing Part# 558-491, Output Harness, and Part# 558-490, Main Harness and Ignition Adapter. I have no way to test the new EFI and don't know how they could miss the 2 most important harnesses. It looks cool sitting on my engine but that's about as far as I got as I cannot test it without the harnesses. Maybe someone at Holley will read this as there are similar complaints for the same missing parts. UPDATE: issue solved Holley shipped the harnesses I needed in 2 days no charge.Update: Unit back at Holley after sending 28 emails back and forth with the tech to get them to open a ticket. After chatting with tech over phone and email for 2 weeks he finally admitted that 10-20% of the sniper systems have issues with tuning. What a waste of time and money, why not admit that upfront and take it back to bench test and fix. Either way car project has been done for over a month now after a year of rebuilding for an EFI system and other items just won't be able to drive it until Holley fixes the sniper unit and gets it back to me. Overall pass on this and spend the money for a ProM unit. ### ⭐⭐⭐⭐⭐ Alcohol in our gas ruins carburators. Join the modern era. *by C***N on Reviewed in the United States πŸ‡ΊπŸ‡Έ on July 1, 2022* The kit did not include everything, so figure it's really going to cost you over 2k$ to get the old boat running. But now the car starts without any blue or black smoke out the tailpipe, runs smooth, I now have 14 inches of vacuum instead of struggling to have enough to not open the power valves all the time, I cannot explain this. I think the kit should come with the progressive linkage instead of the "all barrels all the time' linkage. I took the back barrel linkage off and am only running the front two barrels till I get the progressive linkage. I may have to update the chip for the progressive linkage to dial in properly, but so far it runs good on two barrel. --- ## Why Shop on Desertcart? - πŸ›’ **Trusted by 1.3+ Million Shoppers** β€” Serving international shoppers since 2016 - 🌍 **Shop Globally** β€” Access 737+ million products across 21 categories - πŸ’° **No Hidden Fees** β€” All customs, duties, and taxes included in the price - πŸ”„ **15-Day Free Returns** β€” Hassle-free returns (30 days for PRO members) - πŸ”’ **Secure Payments** β€” Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** β€” Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.co.uk/products/39352531-holley-550510-electronic-fuel-injection](https://www.desertcart.co.uk/products/39352531-holley-550510-electronic-fuel-injection) --- *Product available on Desertcart United Kingdom* *Store origin: GB* *Last updated: 2026-05-19*