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Injector Size Question

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  • Injector Size Question

    I have the original Pro-Flo (SBC) from about 2000, which I bought used in '04 0r '05, I want to run a 383 with about 470 HP, can I increase the fuel pressure to 70 PSI to do that on this old unit? I am willing to get a new inline fuel pump to do it.

    (I NEVER got this unit running, hopefully everything works, I did get a new chip, and a O2 sensor almost at the time I got it back in '05)

    Not sure if this is the best place to post this question.... sorry if it should be elswhere..

  • #2
    Those kits shipped with either 29(white band) or 35(green) lb injectors. The 29's are good to 450 at 58 psi and the 35's are good for 550. I don't like to make drastic fuel pressure changes as it affects all of the tuning because the injector behaves differently with higher pressure.


    • #3
      I thought everything was running 43.5 psi fuel pressure.
      My injectors have green tops, they are a large diameter body, silver with a green top, they look very similar to a bosch injector that comes stock on a mid 90s LT1 about 3 inches tall


      • #4
        Weren't you just talking about running 70 psi of fuel pressure? So obviously you'd have some means for running more than 43 psi of fuel pressure so no, not everything runs at that pressure. If using an adjustable fuel pressure regulator, you can run whatever fuel pressure you want within reason. Steve's point is that with 35 lb injectors at 58 psi of fuel pressure, you can support up to 550 hp. You say you have green injectors which leads us to believe you have 35 lb injectors which are good to 500 hp at 43 psi of fuel pressure. Since you're expecting to make less than 500 hp with your current engine combo, I'd say you're totally fine as is. Fire that baby up and start tuning.