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Holley Sniper EFI Master Kit with Shiny Finish


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Holley 550-510K
More than 10 available
Sniper EFI Master Kit
  • Sniper Self-Tuning Shiny Throttle Body
  • 3.5" Touch Screen
  • Fuel System Kit
  • Free Shipping - Ships

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    550-510K is rated 4.4 out of 5 by 10.
    Rated 5 out of 5 by from Holley carb - injector replacement Prompt delivery at a reasonable price.instructions were helpful and complete. I’m delighted with the performance of the Holley product!
    Date published: 2021-02-17
    Rated 5 out of 5 by from easy to install this holley sniper efi was easy to install in my 1940 ford coupe it really woke up my 347 stroker!!!!!! get read of ur carb buy HOLLEY SNIPER!!!!
    Date published: 2021-02-14
    Rated 5 out of 5 by from Finally! I purchased this after going through 3 carboretors which never ran the way I wanted. I installed the Sniper, which was really easy. It took 2 days for the complete install. I started the car and within a half hour it was running better than I ever had. The "stumble" was gone! It came with everything I needed. You won't be sorry!
    Date published: 2019-10-10
    Rated 5 out of 5 by from Great addition At the price point of these new systems, there's no reason not to switch to EFI these days. Driveability and throttle response has improved tenfold. A slight 'slurping' sound similar to the rear barrels opening on a vacuum actuated carb that is more prevalent than on the carb but I kinda think it's a cool sound (let's you know that its sucking that ait and powering up) and frankly its a small price to pay. I suspect it's the air drawing through the smaller venturi opening. Maybe Holley fixes it going forward, maybe they don't. I'd be fine either way. My worried about noise from the fuel pump were unfounded; can't hear a thing. Great, great product. So THAT'S what a 383 is supposed to feel like? Here I thought 'cranky V8 that can't run cooler than 180 degrees' was the best I could do. Nope - this thing feels like a modern performance engine now.
    Date published: 2017-06-30
    Rated 5 out of 5 by from Big performance increase to our 454! We did not think it would make that much of a difference to our 454 but the power increase is amazing! Starts so much easier also. Installation was a little involved as we were putting this on a 68 impala and had to run a return gas line to the tank. Other than that installation wasn't too bad. Holley will provide great help you if you call them also.
    Date published: 2017-05-29
    Rated 5 out of 5 by from Sniper Install I bought this unit and gas tank for my 67 Mustang. The car has a 428CI FE, 10.5-1 compression and has always been a bear to start when cold. It would just turn over, cough etc for several minutes. Just finished the install and the car fired right up away. Didn't even have to hit the gas pedal. After fighting with this for many years it was great to have it fire up right away. Wished I had done it earlier. But it is still winter here and have not had the chance to put some miles on it will have to wait until spring.
    Date published: 2017-02-14
    Rated 4 out of 5 by from easy instructions everything is great. But before you buy you read the defination and it shows that it controls the timing. It does but you will need to spend another $233.00 for a different distributor. Still in process of installing. But very easy. After i purchase the distributor and hook up i am sure it will be worth it. no cold starts, no hesitation, and should be better on gas than a carb that may be running to rich.or blowing power valves in the carb. A decent carb is around $400.00 and then you will need to change power valves and jets, and readjust floats depending on how your vehicle sits. Depending on how radical your engine is. building a 1964 c-10 pro-street. up to 650 hp. instructions talk about cam and crank sensors. newer engines have these but older ones do not. But instructions are not talking about these sensors but is talking about reading these which the new distributor does this. you can get away from installing a new distributor but it will not adjust the timing. and the whole part of buying this kit is for doing everything. good luck. if you read reviews on FITECH EFI has to many computor issues.
    Date published: 2019-11-25
    Rated 4 out of 5 by from Nice but a bit misleading I bought this kit because It's advertised as being easy to use, just install, tell the ecu a few basic details and drive. While that is mostly true, there are some quirks that you will more than likely have to *tune* out of the system yourself. The throttle body makes alot of whistling sucking noises that you have to buy a carb spacer to get rid of. The standard throttle linkage is a bit aggressive in that it opens the primaries and secondaries at the same time. Might not be so bad for an automatic but with my 4spd it was too on/off on the throttle response. So again you buy a another part to fix it, I put a progressive linkage on mine to smooth out the throttle. Otherwise my main gripe is that my truck and alot of other people has sort of stalling issue when you come to a stop where the engine will drop rpm rapidly go lean then catch itself and go back to idle. Holley tech takes a week to respond to my questions and hasn't been very helpful. I think this kit is great for someone who has some mild tuning experience. But for someone who doesn't your going to have troubles and hopefully you can find someone who can help.
    Date published: 2019-06-28
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    Just to make sure this will plug into my MSD distribution and MSD box? 

    Asked by: NagsCustom
    Yes.Compatible with MSD
    Answered by: Kenny U
    Date published: 2018-11-02

    Do they make a Sniper efi kit for a sbc tunnel ram?

    Asked by: dalton32
    You can use 2 of thee throttle bodies on the tunnel ram to make it work.
    Answered by: Rusty B
    Date published: 2018-09-17

    Will this fit a Ford 312 engine?

    Asked by: fratchj
    These kits are made to fit almost any engine. As long as you have a 4150 carb flange this EFI unit can be configured to work for you.
    Answered by: Flanary
    Date published: 2018-11-19

    What is the filter neck height and can this system be used with capacitive discharge ignition 

    Asked by: Rob76400
    It is a standard carburetor size 5 1/8". this can be used with a CD ignition.
    Answered by: Rusty B
    Date published: 2018-02-28

    Parts needed to in a sniper efi on a stock 1977 ford f250 with a 460 automatic transmission.

    Asked by: Bo 2018
    This should work on your truck, you may need to re-use some of the linkage components from you carburetor for the transmission.
    Answered by: Rusty B
    Date published: 2021-01-15

    In one of the questions your answer says the EFI systems operates at approximately 58 psi. However, it appears that the fuel pump sold on Jegs operate at less than 58 psi and most are measured by a GPH unit. What fuel pump do you recommend?

    Asked by: clint01310
    Holley recommends the use of their 12-920 . These are the specs for the fuel pump; 80 gph @ 15 psi/67 gph @ 45 psi 480 pph @ 15 psi/402 pph @ 45 psi 5 amps @ 15 psi/8 amps @ 45 psi Supports TBI up to 800 HP
    Answered by: Rusty B
    Date published: 2018-11-19

    Can I run this with existing mechanical fuel pump, or do I have to use an electric fuel pump? Thanks.

    Asked by: RE from Miami
    The Sniper EFI systems are designed for an operating pressure of 58.5 PSI. An electric fuel pump is ideal and recommended to accomplish this. Carbureted engines with a mechanical fuel pump typically run between 5-7 psi.
    Answered by: Tech Support
    Date published: 2017-12-28

    Is this a blow Thur , is it capable of being used with a power adder, turbo, procharger ?

    Asked by: Duger
    This is not for use with power adder such as turbo or superchargers.
    Answered by: Jegs Tech
    Date published: 2020-09-25
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