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Thread: Converting to the 4500 Stealth Sniper EFI.

  1. #1

    Default Converting to the 4500 Stealth Sniper EFI.

    I'm gonna built a SBC 400ci with a Vortech V7YAI-B supercharger. It was a nitrous engine before, but now nitrous is expensive to buy. So I'm wanting to order the 4500 Stealth Sniper EFI for my small block and I have no idea on EFI, but I saw this Sniper EFI, and it’s the simplest way to convert to EFI. I have a MagnaFuel 500 pump as for my fuel and also the MSD 7AL3 red one with the HVC 2 coil and a crank trigger with a Pro Billet distributor. So can I keep what I have to use the EFI? What do I need to order to convert to control timing for boost and also fuel, etc. I appreciate the responses and help. Thank you, Tommy

  2. #2


    It’s 1500 cfm.

  3. #3


    Have you bought the Sniper or the intake yet? The 4500 has the Dominator flange, so make sure it matches your intake.

    Having done boost and EFI I really recommend you only do one at a time. The learning curve for blow-through is large and the learning curve for EFI is even larger. Add them together and it can really be tricky. I did boost 8 years ago and the Sniper just this year. As to your questions, you can certainly re-use some of your parts but you have to look at the whole system.

    For fuel, do you have a sump setup today? Are you using a return style fuel system? Look up the specs on that pump and see if it will support 60 PSI +. However, much boost you plan to run. You'll need a boost referenced regulator.

    For ignition I really recommend you go with the full HyperSpark system with distributor, CD box & coil. It makes it very much plug & play and really helps lessen the learning curve. Also, the HyperSpark distributor is a Hall-Effect type, which greatly lowers EMI. Your Pro Billet is a Magnetic pickup. You can sell your old stuff to raise money for the new stuff. Just my opinion though.
    69 Camaro
    400 SBC, ProCharger D1SC
    1.302 60', 5.95@116.4 on pump gas

  4. #4


    I have the Super Victor 4500 flange and the carb I have is a 1350 cfm. I have a 5 gallon fuel cell, rear mounted pump. The pump has the return line back to fuel cell. I don’t have a return line from the regulator back to the cell. Is the HyperSpark better than 7AL3? Why is that about doing N/A first, and then boost later?
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  5. #5


    You can certainly do both at the same time, that is just a lot of variables to troubleshoot if something goes wrong on the initial startup.

    I believe with that pump you'll need to plug the return line that's on the pump because it limits pressure to 25-36 PSI at the bypass. You need to call MagnaFuel to see if that pump will support 60+ PSI. Your regulator in the engine bay will need to be able to regulate to 60 PSI and be boost referenced.

    You can use the 7AL3 box if you want. Just be sure to wire it to the Sniper accordingly.
    69 Camaro
    400 SBC, ProCharger D1SC
    1.302 60', 5.95@116.4 on pump gas

  6. #6


    What about the crank trigger? I can keep that on the crank or I won’t be able to use that?

  7. #7


    Hopefully someone else will chime in. I don't have a crank trigger, so I'm not sure.
    69 Camaro
    400 SBC, ProCharger D1SC
    1.302 60', 5.95@116.4 on pump gas

  8. #8


    Why does the Sniper X Flow support more HP than the 4500?

  9. #9
    Join Date
    Dec 2009


    Larger fuel injectors.
    The Sniper Stealth 4500 is rated for 1250 F/I, or 1500 N/A HP (eight 100 PPH injector).
    The Sniper XFlow is rated for 800 N/A HP (four 120 PPH injector), or 1375 F/I (eight 120 PPH injector) HP.
    May God's grace bless you in the Lord Jesus Christ.
    '92 Ford Mustang GT: 385" SBF, Dart SHP 8.2 block, TFS TW 11R 205 heads, 11.8:1 comp, TFS R-Series intake, Dominator MPFI & DIS, 36-1 crank trigger/1x cam sync, 160A 3G alternator, Optima Red battery, A/C, 100HP progressive dry direct-port NOS, Spal dual 12" fans/3-core Frostbite aluminum radiator, Pypes dual 2.5" exhaust/off-road X-pipe/shorty headers, S&W subframe connectors, LenTech Strip Terminator wide-ratio AOD/2800 RPM converter, M4602G aluminum driveshaft, FRPP 3.31 gears, Cobra Trac-Lok differential, Moser 31 spline axles, '04 Cobra 4-disc brakes, '93 Cobra booster & M/C, 5-lug Bullitt wheels & 245/45R17 tires.

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