Roller cam valve springs??

Discussion in 'Race 400/430/455' started by dan zepnick, Sep 15, 2022.

  1. dan zepnick

    dan zepnick Well-Known Member

    So I'm trying to get further on my tomahawk build. Head guy gave me specs we want to find springs for. No luck so far. Cam is .704/.717? Lift. Solid roller.He wants 200# seat pressure and 700# open. I can find some PAC springs that are 250 seat and 659 open. This is what the tech guy at PAC recommend. What are you guys using? Part numbers would be good. Heads are track elimator that hopefully will flow around 380?? Thanks.
  2. Jim Weise

    Jim Weise EFI/DIS 482

    Scroll down the page there to the 1.300 diameter OD offerings.. these springs completely eliminate the rocker/spring interference issues we suffered from for years. I am assuming you have not had the T/D individual rocker mods done to that head.

    I have used the 427 spring successfully several times.. you have to run a no insert viton seal, for clearance for the inner spring. Basically just the metal seal body pushes over the valve guides.. get the matching spring locators, titanium retainers and keepers with it.

    Good stuff empties the piggy bank, so be prepared..

    lt1b4c and dan zepnick like this.
  3. BrianTrick

    BrianTrick Brian Trick

    I can see what mine are. I also run a Jesel system and the heads are beyond modified.
    dan zepnick likes this.
  4. Staged70Lark

    Staged70Lark Well-Known Member

    I ran the K Motion K950 spring but I had longer valves with a +.050 keeper
    1.550 diameter double M-400 spring with damper good for camshafts up to .750 lift. 245# @ 2.000, 690# @ 1.300, coil bind at 1.150.
    dan zepnick likes this.

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