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    Another rear end swap question

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    radioguy
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    Another rear end swap question

    Post  radioguy on Sun Jul 03, 2016 7:00 pm

    I just got a 95 9C1 posi rear in 3:08 and am going to swap it into my 78 Caprice two door coupe. My car came with a 350 4 barrel and turbo 350 transmission and an 8.2" 10 bolt. The question is will I have to shorten the driveshaft? I see two different answers to this on various forums. One is yes I have to shorten it 1 inch. The other is the rear is a bolt in. I'm new to the forum but not new to the cars- this is B body number 6 for me but the first one I have done major mods to.
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    Myloth
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    Re: Another rear end swap question

    Post  Myloth on Sun Jul 03, 2016 8:54 pm

    I didn't have to touch the driveshaft but I swapped a 7.5 open rear for the later Posi rear. The Admin might now if there is a difference

    between the two or not he's familiar with the 8.2 I believe?
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    CamaroKid
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    Re: Another rear end swap question

    Post  CamaroKid on Tue Jul 12, 2016 6:10 pm

    Just measure the distance from centerline to yoke on both axles.
    Should tell you right away if you have to mod the driveshaft.


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    terry cronk
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    Re: Another rear end swap question

    Post  terry cronk on Wed Jul 13, 2016 9:23 am

    I just swapped my 8.2 10 bolt out for a 1992 8.5 10 bolt.

    I didn't have to shorten the driveshaft. But it was tight in the first place with the 8.2.

    The bearings should be the same.

    Make sure you have newer control arms for that 78. They get pretty ratty at that age.

    Plus on mine the arms were cut off. The bolts were rusted in. And I bought the newer stage 2 arms.

    Good luck.

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    Myloth
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    Re: Another rear end swap question

    Post  Myloth on Wed Jul 13, 2016 11:42 am

    Get yourself a pair of solid upper arms for 150 and toss that stamped steel junk in the recycle bin. I find the stock rear arms (excluding 9c1)

    to be the only OEM parts of the Chassis \Suspension of these cars I find Offensive because they are so poorly made and add a ton of flex.

    The 9c1 lowers are pretty good but the stock Uppers are WEAK, I installed SouthSide Machine Uppers and Lowers and my rear is so tight the

    only flex at all is the old body mounts.
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    Re: Another rear end swap question

    Post  GM B-Body Forum on Thu Jul 14, 2016 9:26 pm

    If your switching from a 7.5 to an 8.5 it was exactly 1 inch on the driveshaft, Im not sure if the 8.2 has the same dimensions exterior wise as a 8.5.


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    terry cronk
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    Re: Another rear end swap question

    Post  terry cronk on Mon Jul 25, 2016 2:01 pm

    When changing over from the 8.2 to an 8.5, the driveshaft was the same length.

    The U-joints are the same also.

    radioguy
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    More info needed

    Post  radioguy on Wed Aug 10, 2016 7:44 pm

    Thanks for the replies about the swap. I put the Spohn Performance rear tubular upper and lower arms on the car last year and also have 95 9C1 front and rear sway bars, lowered 1.5" in the front . Air Lift bags in the rear and KYB gasadjust shocks front and rear. The car will out handle my modified Crown Vic P71 with ease. I replaced the entire front suspension and steering linkage too. Trouble is The 2.56 rear gear and tiny brakes. The car has waaayyy too much horsepower to be fooling with 9" drums. Next question: The 95 9C1 rear I have came stripped. I need the rear brake hose mounting brackets and don't even know what they are supposed to look like. Can I get them from GM (or somebody on the forum) or do I have to fabricate?

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