10' Slick Under a Diplomat

Chassis, Suspension and wheels

  1. CM360

    CM360 Well-Known Member

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    Going to take my '80 Diplomat and ready it for 12.50 index racing. Anyone fit a 10" slick under one?
     
  2. BudW

    BudW Moderator Staff Member

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    Sounds like fun!

    Note: does your title says 10’ (10 foot) slick?
    I can’t comment about fitting a 10” slick (or tire) under one, yet.
    BudW
     
  3. CM360

    CM360 Well-Known Member

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    The 10' slick refers to the leaking trans in the Diplomat.
     
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  4. MiradaMegacab

    MiradaMegacab Well-Known Member

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    Obviously wheel BS is a factor, what axle too? B or a wider E body 8.75?
    The first clearance issue is between the inside of the tire and the front part of the wheel well, then the front of the tire to the leaf springs..
    Simply moving the rear axle back 1 to 1.5" usually overcomes the clearance issues.
    Tire height is a factor too.
    I ran a 30X10 tire by moving the axle back.....
    Section width is another factor..... lol
     
  5. CM360

    CM360 Well-Known Member

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    That's an additional 1-1 1/2" to the wheelbase on cars that have the boat anchor bumpers hanging out in the breeze. Its a solution that adds other issues.
     
  6. MiradaMegacab

    MiradaMegacab Well-Known Member

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    Yup, and mini tubbing does nothing as the front segment of the leaf spring is a problem.
    What's the intended use for your car? (Drag Race, AutoCross, ProStreet)
    Spring relocation kits only get you so far.
    Ladder Bar with coil overs or 4link might be the way to go, if you're doing a serious drag application.
     
  7. Locomotion

    Locomotion Well-Known Member

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    I agree that the wheel well tub is an issue for tire clearance at the front. I dented mine for clearance. But it's the leaf spring orientation that can cause a sidewall clearance issue at the back. It won't give a lot more room and backspace still has to be just right, but you can get a little bit more clearance with just E-body 3/4" offset shackles. The OEM leaf springs are actually toed-in, making clearance less at the back of the tire. The 3/4" shackle helps to straighten them out and there seems to be enough "slop" at the front to do it. But I confirmed that it's not legal for my racing application. I got 9x30 Hoosier radial slicks on 10" wheels to fit on my wagon, but I don't remember if the previous owner had already clearanced the front of the wheel well or not. It's best to do when switching to an 8 3/4 rear so the spring pads can be relocated. Yes, a lot of work for a little gain, but an option nonetheless. But the 8 3/4 and corresponding shock plates provides for a wide variety of race shocks. Front race shocks are another, bigger issue. Late '60's B-body 8 3/4 is suppose to be the closest width and the pads may line up as is with the offset shackles. (I read an article about it a while ago but don't recall where.)

    Axle dimensions: Dodge, Chrysler, Plymouth Rear Axle Dimensions

    (I believe the last 2 listings are suppose to be 9 3/4").
     
    Last edited: Nov 12, 2017
  8. Oldiron440

    Oldiron440 Well-Known Member

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    You don't need a 10-inch slick to go 1250s, in fact it will probably slow you down.
     
  9. BudW

    BudW Moderator Staff Member

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    That chart is helpful – but is not entirely correct.

    This chart is still under construction – but is a lot more correct.
    Note: I still need to add Jeep, Dakota’s and a lot of other Mopar's into the mix.
    Note: green cells - data not confirmed (or known), yet.
    Diff Excel 1.jpg

    Diff Excel 2.jpg
    BudW
     
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