8 3/4 disk vs drums

Discussion in 'Transmission and Drivetrain Tech' started by Elwood blues, Aug 12, 2018.

  1. Elwood blues

    Elwood blues New Member

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    I recently acquired an original A body 8 3/4 housing for my 71' Scamp. i currently don't have anything else for it but i plan on just ordering new axle shafts for it and have my eye on a couple carriers on craigslist. i have 2 questions first one is would it be easier/cheaper to just throw drums on it or since its pretty dismantled would it be more worth it to convert it to disks? second question, when going with drums again can i get an 8 3/4 from an E or B body and steal brake parts like backing plates, drums, shoes, cables, ect. and put them on the one for my Scamp?
     
  2. Ted Carlson

    Ted Carlson Well-Known Member

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    Disks on the front and drum brakes on the rear are very ok unless you are going to road race.
     
  3. Fisho

    Fisho Well-Known Member

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    I'm going through the same thing. Just went bbp on my Duster and need to figure the brakes. I think I'm going with the scarebird brackets and sourcing calipers and rotors from the parts store. It's going to work out almost the same money wise as sourcing out all the drum brake parts I need.
     
  4. 72bluNblu

    72bluNblu FABO Gold Member FABO Gold Member

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    Original A-body axles are all small bolt pattern (5x4"). If you're buying new axles, you should convert to large bolt pattern (5x4.5"). If you convert to the 5x4.5" pattern, you can get drum hardware off of any large bolt pattern car (or even a few trucks). The 10x2.5" BBP brakes were used all the way up to the 90's on some cars.

    What you can't do is mix and match small bolt pattern axles and brakes with large bolt pattern axles and brakes. The axle flange offset is different, so the backing plates are different for each set up.

    If you're just planning on a street car, the drums will serve you just fine. But rear disks can make a pretty decent difference, Mopar Muscle did some testing when they converted a Dart Sport from rear drums to disks...
    Rear Disc Brakes - All Bound Up - Mopar Muscle Magazine
     
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    • Elwood blues

      Elwood blues New Member

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      Thanks for all the info, when i get new axles i plan on getting the larger 5x4.5 ones to match the disk brake conversion in the front. I think going with the drums in the back sound like it would be easier and cheaper to do and will work just fine.
       
    • sireland67

      sireland67 Well-Known Member

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      I used everything off a lowly 7.25 rear brake wise, using Dr. Diff 4.5" axles.
      Bolt on and go, cheap too because I had two of the big bolt rears.
       
    • tonysrt

      tonysrt FABO Gold Member FABO Gold Member

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      After doing Disc brakes for years with no problems and then fighting with all the springs on drum brakes, I vote for disc.
       
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      • Dana67Dart

        Dana67Dart Most undignified way to get to Colorado!

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        If you go rear disc remember to remove the valve in the outlet if the master cyl for the rear brake cir.
         
      • dano

        dano Evil Handy Man

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        Since you have nothing the Dr Diff rear disk kit is hard to beat, especially if you add the 13" front disks.

        Tires go a long way to help braking too, so plan on looking at 17" and up because the 15" stuff is 1980's or older for compounds and design (and way overpriced for that giant wiggle wort side wall), 16" you can get some better stuff but expensive, go to 17" and the world is you oyster.
         
        Last edited: Aug 13, 2018
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