550-511K

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Part # 550-511K

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Emissions

This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles.

See Emissions Details

Bangshift.com: The Caddy Powered C10 Gets A Holley Sniper EFI

RacingJunk.com: Installing Holley's Sniper EFI System

FullSizeBronco.com: Holley Sniper EFI Install

HOT ROD Tests Holley’s Sniper EFI

Accelerometer Support	No
Air Metering Style	Speed Density
Boost Control	No
CAN-BUS Support	Yes
Coil Per Cylinder Ignition Support	No
Datalogging Support	Yes
Distributor Included	No
Dry Nitrous Control	No
e85 Support	No
EGT Support	No
Emission Code	3
Forced Induction Support	Yes
Fuel Filter Included	Yes
Fuel Hose Included	Yes
Fuel Injectors Included	Yes
Fuel Pressure Regulator Included	Yes
Fuel Pump Flow Rating	240 LPH
Fuel Pump Included	Yes
Fuel Pump Type	Inline
Grade Type	Performance
Ignition Timing Control	Yes
Individual Cylinder Fuel Corrections	No
Intake Manifold Included	No
Knock Retard Support	No
Multi-Stage Nitrous Control	No
Progressive Nitrous Control	No
Self-Tuning	Yes
Throttle Position Sensor Included	Yes
Traction Control Support	No
User-Tuneable	Yes
Warranty	Two Year Standard, Extended Via Product Registration
Wet Nitrous Control	No
UPC	090127739877
Part Number	550-511K

This part is legal for sale and use on Uncontrolled (Non-Emissions Controlled) Vehicles.

The following vehicles are considered Uncontrolled (Non-Emissions Controlled) Vehicles:

1965 and older U.S. manufactured California Certified vehicles
1967 and older U.S. manufactured Federally Certified vehicles
1967 and older Foreign manufactured vehicle

WARNING: It is against the law to install this part on an Emissions Controlled Vehicle

The following vehicles are considered Emissions Controlled Vehicles:

1966 and newer U.S. manufactured California Certified vehicles
1968 and newer U.S. manufactured Federally Certified vehicles
1968 and newer Foreign manufactured vehicle

Holley EFI Dealers
Do you need a custom kit built for your application? Do you need a system installed and tuned? Click here to find the Holley EFI dealer in your area!

Quickstart Guide
Quickstart Guide

Instructions for Part# 550-511K
Instructions for Part# 550-511K

Sniper EFI SD Card Contents
Sniper EFI SD Card Contents

Instructions - 199r11031r.pdf

Instructions - 199r11369.pdf

Instructions - 199r11194.pdf

Instructions - 199r11193.pdf

Two Year Standard, Extended Via Product Registration: See Details

Have a question about this product?

Question
Is there a specific distributor needed to run with the sniper EFI kit?
By Karl H. on April 15, 2018
Answer
The most basic installation only requires a tach input to operate. This is generally provided by the negative side of your ignition coil. If you are seeking to utilize ignition timing control, then we recommend using one of our Holley EFI Dual Sync Distributors.
Helpful?
Question
Do I need two o2 sensors sense I am running true fuel exhaust ? With the sniper 550-511k kit
By Leonard H. on April 15, 2018
Answer
The included O2 sensor is all that is needed for our Sniper TBI systems.
Helpful?
Question
I have a 1980 Pontiac Trans Am with the 4.9Liter Turbo. Is this the right system for my vehicle, if not which one is? Thanks
By Robert V. on August 21, 2019
Answer
Your engine came with a spread bore carb on it from the factory. Unless you have swapped intake manifolds to a 4150 intake. https://www.holley.com/products/fuel_systems/fuel_injection/sniper_efi/sniper_efi_quadrajet/ This product would be a better direct bolt-on choice for your intake manifold. Being a boosted engine, it will require some laptop tuning to get the calibration dialed in 100%. The software is free to download and very easy to use. If you would like to try it out before you purchase anything, it can be found here. Go to the below link, and scroll down to Sniper EFI Software. https://www.holley.com/support/resources/#Fuel_Injection
Helpful?
Question
Does this kit include wiring for the electric fuel pump including relays?
By Vincent F. on April 27, 2018
Answer
Yes, the fuel pump relay is built into the Sniper EFI Main Harness.
Helpful?
Question
Can the fan/ fans be programmed to come on with the AC ground signal?
By Jimmy G. on September 15, 2019
Answer
Yes. The ground output will need to trigger a relay to power the fans.
Helpful?

Reviews

4.7 out of 5 stars

5 star
83%
4 star
13%
3 star
0%
2 star
4%
1 star
0%

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Carburetor to EFI

By christopher l on February 14, 2018 | Verified Owner

It was time to up grade my 72 Chevy Blazer after stalling out climbing hills when off roading. The Holley Sniper EFI was a fairy easy install following the included instructions and online videos. The Blazer starts in seconds and no more raw fuel burning the eyes. It’s been all smiles driving the Blazer now.

Sniper with dual sync distributor

By Troy G on February 14, 2018

Put my sniper on a Chevy 350 and so far nothing but smooth sailing. The timing control is also pretty painless. The only con I can think of is that your dual sync + sniper setup has a lot of extra wires and they aren't arranged in a way that lends itself to a clean installation. Holley should redesign some of the harnesses and modules needed for my type of setup and make it more streamlined. The shop did a good job, the setup is just too ugly to make look good without going out and buying extra stuff to dress and cover the wires. The sniper may be plug and play the distributor is NOT.

Sniper EFI kit 550-551k

By Justin K on February 14, 2018 | Verified Owner

Installation of the kit itself was pretty easy. Initial set up and programming was a breeze. Setting the throttle position and response was a little difficult for me and the instructions didn't seem very clear, but that could just be my fault. The install video was much more helpful to me than the written instructions. If this works as well as I hope it does, I look forward to purchasing another for my 65 malibu.

Ditch the Carb

By steven v on February 15, 2018 | Verified Owner

This complete kit was very easy to install and tune. Throttle response is amazing and it made my ZZ4 come to life. I would recommend this kit to anyone!

Sniper kit

By derek o on February 15, 2018 | Verified Owner

Opened the box and found this kit is awesome it has everything and looks great. Instructions are super easy to follow and complete for all set-ups. Great product for the money car runs great after install.

sniper master kit

By Brandon S on February 16, 2018 | Verified Owner

recently purchased the 550,511k kit from holley. Thought it was going to be a huge hassle to install, but thanks to holley detailed install instructions it turned out to be pretty easy to install. The hardest part of the install was the fact that my mustang did not come with a return line for the fuel. The second great thng about this system is how well the self tuning works, my car started up on the first time after the install. I would highly recommend this product, is simple to advanced tuning ability makes it great for everybody from someone just trying to get ride of a carb to someone doing advanced tuning for a street/strip car.

1990 454SS

By Steven L on February 16, 2018 | Verified Owner

I installed this on my 1990 454SS silverado and it performs flawlessly. Great product with great instructions.

Sniper kit

By Jack P on February 21, 2018 | Verified Owner

With the help of some youtube videos for fine tune (iac for idle), this setup works good. I installed it on my 66 FE390 Fairlane GT and have a hundred miles on it now. The engine runs smoother and has quick throttle response. My garage doesn't have the rich exhaust smell, nor the gas smell when I park my car in it.I did not use the MSD distributor features yet. I'll be upgrading the alternator from 1g to 3g soon to eliminate some voltage issues. It took a few days to complete the install, linkage mod, and tank mods, but it was well worth it so far.

Holley EFI

By Ernesto P on March 7, 2018 | Verified Owner

Great product extremely pleased with the shipping speed and most importantly the product itself. Instructions are clear and easy to fallow. After install truck ran so much smoother and now I'm saving on gas as well!!!

Holley Sniper EFI Master Kit

By Dale J on March 8, 2018 | Verified Owner

We put this on our 1966 Mustang with the 289.So far so good. Very easy to install and it looks great.Holley should be proud of this one

Sniper on carburetored Ls 2 motor!!!!!!!!

By Dan E on March 23, 2018 | Verified Owner

I'm running a Ls2 carburetored motor with Brian Tooley stage 4 cam, ported and polished heads and intake by Kimm Barr in Garland, Texas. The head flow right at 300. Motor was a beast with a 950hp carb. I was concerned with the performance of the Sniper to run this motor. Surprise, way smoother idle,cruise, and rediculous throttle response. The only issue was getting the info to hook it up to the Ls based 6LS msd box. After I did my research, because holley kept saying the grey wire, I figured out it is the yellow wire out of the MSD 6LS box to trigger the tach iutput. Figured that out and bang, off and running. Very happy so far. Crazy but the idle sounds in no way as radical or, weird enough,loud. Much more quite ride. Got more to learn but a bad ass kit.

Dose not come with O2 sensor

By Richard Z on April 10, 2018

This kit dose come with O2 sensor you need to use ..for 1250.you think they would tell you ... And it's on back order 3 weeks out holly.com dose not state you need to buy sensor when calling Tec service. Also very bad customer service on hold for 20 mins transfers 3 times then back to teck service I hope the product works as advertised Rick

This kit is awesome!

By Spike S on June 7, 2018

Very easy to install, everything you need in the box, great instructions and the video is even better. Made my 455 Buick motor come to life. Great kit and great price

pump is 125 psi and the hose SAE 30R14 is maximum 50psi

By Robert E on September 30, 2018

first it looks perfect and compete the working we wil do it after the last event pump is 125 psi and the hose SAE 30R14 is maximum 50psi when the pump is max en the carb is blokking we think we need a other hose the r9 i like to no before we starting the rebuld from ouder 520hp ac cobra ok everything is ok now after some emails

Sniper Master Kit

By Shaun M on March 25, 2019

The core of this kit is great, the install is not as intimidating as it might seem; however the videos created by Holley and uploaded on this site misrepresent what is actually in the kit, be aware that you will not receive any throttle linkage components or connectors as stated. I am not sure at what point they stopped providing these parts in the kit it was just something I did not expect to chase down after getting into the install (Holley you should put some notes on your install videos indicating that the linkage parts / brackets and electrical connectors are no longer provided). Also depending on the vehicle you are installing my my case a 1972 Camaro; you will also need to source a cover plate and gasket for your old mechanical fuel pump removal and also a fuel return line; these things I was aware of going into the install. Also pre plan how you will mount the fuel pump and filters, these need to be mounted close to the fuel tank a lowest level and Holley can't solve that for you as every car is different; this was expected on my end just a heads up.

Brought my 460 back to life

By Cody K on May 26, 2019

Overall very happy with this kit, super easy to install. I does not come with any linkage for the throttle cable or trans kick down rod, also no fuel pump block off plate or electrical connectors that were mentioned in the install video. Once installed set up with the tuner was super easy and truck fired up on the first try. No issues with it at all yet.

Holley Sniper twin marine application

By nicholas h on May 27, 2019

So i was looking for a way to gain some range on my 33' Aquasport offshore fishing boat. I have a twin 350 mercruiser setup in my boat. I had a hard time getting them started cold and i only had a range of 75 miles and that was a big limitation. After this installation she starts like a car with better performance and I have increased my range by 25%-30%. the install was relatively easy other then a few issues with it being a marine application. The first and largest was the O2 sensor. I tried to install the bung in the topside of the pipe but this didn't work do to the exhaust pipe being to large i couldn't get enough flow fast enough at idle for a good reading. I was able to make a fitting to put the sensor in the manifold and this and slowing the closed loop reaction down solved the issues there. The other was to be sure the pump is mounted to the bottom of the tank for best performance. If you have any issues the first question techs will ask you is whats you fuel press? I mounted a holley mech. gauge on the inlet of the TB so I had a solid reading. I had one of the kits had the IAC motor fail but they sent me a new motor with no problems. The main challenge is getting it learned but once she has learned the table this is a awesome kit.

Jeep 4.6 stroker, now with Sniper EFI

By David S on July 25, 2020

I've had mine installed on my 1984 CJ7 with a 4.6 Newcomer Racing engine for about a year now. It runs so much better, and stronger than it did with the 390 carburetor that I took off it. I just purchased a Holley Hyperspark Distributor, CD box, and coil. This will be awesome!

1984 K10 sniper

By Micheal C on June 4, 2021 | Verified Owner

I got the master kit and was very easy to install. I’m still dialing in the sniper. I wish it came with fuel pressure gauge and a tune for higher altitude as I live 7000 above sea level. I only have a 100 miles on it but has been good so far as this is my daily driver. I highly recommend this setup as it has almost everything you need.

Sniper 550-511K master kit with Hyperspark on a Buick 350

By Spencer R on June 5, 2021 | Verified Owner

Complete kit. The only things you will need to source is a new throttle cable, and modify your existing bracket or purchase a FITECH GM throttle cable adapter. You will also need a throttle return spring. Install was straightforward. Follow the quick-guide installation instructions. Use solder heat shrink connections only. Started up and ran great on first crank. Self tune works great, especially if you follow the Holley videos on TPS and IAC idle settings. I found that the EFIPRO throttle lever extender and progressive linkage together made the sniper much more streetable. It starts snd runs like a dream. Note: handheld is a little finicky. I strongly recommend downloading the sniper tuning program, and using the Holley software to tune your fuel and ignition curves.

Better than the others

By James T on June 29, 2021

I have installed 3 EFI systems from another company F*t**h. They all had issues even on stock to mild engines and a pain to tune using there supplied handheld. Let me say the Sniper was similar in install for wiring and such so follow instruction with routing wires. Started 1971 Blazer up and only adjusted AFR and runs amazing. Pay the couple hundred more bucks and buy a product that works out of the box with out spending hours to days tuning. Two thumbs up Holley.

installed on 1983 camaro

By Jason H on July 29, 2021

installed the master kit on my camaro .. went pretty smooth .. just over 5 hours start to finish .. works great . engine didnt even rotate over 1 time before it fired..

Sniper Kit

By Jacob M on September 21, 2022 | Verified Owner

Ok, so if you are wondering is it worth the money, YES, will it work like they say, YES. Will the stand behind it if it has problems 1000% yes. I own 4 sets of these, and out of the 4 one of them one has had an issue 2 different times. The first time Holley took it back and worked on it and sent it to me, and about 6 months later started having a problem again, now keep in mind this is like 2 plus years after I bought it. After I sent it back the 2nd time they ran test and said that they were just going to send me a new replacement, WAIT WHAT! Sure enough, they did, I WILL ONLY BUY HOLLEY PARTS FROM HERE ON OUT. If they are going to stand behind their stuff like that, WHOA I am in. Even before this, I would go to car shows and tell people to buy and they would love it, I love it, hit the key and it fires right up and runs amazing. I am also that guy that read reviews to see if it is worth but never seem to write one, but I have to make sure people know that this is one great product and that Holley stands behind it a 1000%.