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  1. #1
    Saving the Manuals every day.. TheBlueMartin's Avatar
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    Rotary valve change/mod

    Does anyone have experiance with changing size on rotary valves? The 657 I have is a 159' stock, but Im wondering how much of a change going to a 147' will have on the low end, and how much it will take away from the top end. Any ideas?


  2. #2
    Saving the Manuals every day.. TheBlueMartin's Avatar
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    So no one has ever ran anything but a stock rotary valve??

  3. #3
    96XPSS's Avatar
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    It's not worth it. You give up max rpms for a better holeshot, and vice/versa. The stock one is best.

  4. #4
    Saving the Manuals every day.. TheBlueMartin's Avatar
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    I already have a new ss 147' lying around, and I may throw it in just for fun and see how it is. However, Ive decided to pick up a carbon fiber 159' to use normally.

  5. #5
    I read in another post that the CF valve isn't advisable due to eating up the cases... I'm sure someone will chime in and let you know.

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