Can I put BBP drums on my 69 ?

Brakes for your Classic Mopar

  1. mbaird

    mbaird mbaird

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    Just curious if there is any reason I couldnt convert my 69 dart to 5x4.5 bolt pattern drums up front ? What would it require ?
    Same with rears....other tgan axles of course.
    It would be easirr to find wheels....
     
  2. Kern Dog

    Kern Dog FABO Gold Member FABO Gold Member

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    It would require some of the same stuff you'd need to swap to discs.

    The B body drums are the only bolt in ones with stock parts. NO A body cars came with big bolt pattern drums.
    To do the B body drum swap, you'd need either the 73-76 A body DISC upper control arms (Which use the B/E larger upper ball joint) OR get the adapter/spacer/shim kit from Dr Diff to retain the smaller upper ball joint UCAs. You'd need 73-76 A body DISC lower ball joints too.
     
  3. 1969383S

    1969383S FABO Gold Member FABO Gold Member

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    Sure you can but why drums?

    Go disc on the front for sure, and aftermarket 4.5 axels are available for the rear.
     
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    • mbaird

      mbaird mbaird

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      Trying to stay simple... I am going to run steelies with dogdishes so the SBP is not a big deal but since I will probably need new drums and racing axles I figured I could just go with the BBP....
      Funny , With all the mopars I have dealt with I never realized Abodies never came with front drums after 72..
       
    • Jimacuda

      Jimacuda Well-Known Member

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      They did come with front drums after 72.
      Four wheel drum brakes were available right thru the 76 model year production on cars built December 31st 1975 or before.
      As of Jan 1 1976 front discs were federally mandated.
      All A body cars with 4 wheel drums were small bolt pattern.
      All disc brake cars built for the 73-76 model years were large bolt pattern.
      The 1973-76 7.25 axles were available in both bolt patterns, 8.25 was large bolt pattern only.

      IMO its not worth the extra effort to convert to large bolt pattern drums. I'd just go with the large bolt pattern disc swap. Much simpler. Much, much simpler.
       
      Last edited: Mar 8, 2017
    • mbaird

      mbaird mbaird

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      I thought I had seen later cars with drums..
      So why is it so much trouble ? Are the spindles diffetent ?
       
    • mbaird

      mbaird mbaird

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      I did not know small bolts were available after 72....interesting !
       
    • 72bluNblu

      72bluNblu FABO Gold Member FABO Gold Member

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      Any big bolt pattern drum set up would require a spindle change too. If you're changing spindles you might as well just go to '73+ disks. All the same things would be needed- new spindles, new lower ball joints, and either LBJ UCA's or the tapered adaptors because all the BBP drum spindles used the larger ball joints. Like the SBP the small upper ball joints were an A-body thing.
       
    • harrisonm

      harrisonm Well-Known Member

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      If you are willing to go to that much trouble, switch to discs!!!!!!!
       
    • SIX225

      SIX225 Well-Known Member

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      Years ago, I thought I read something about using AMC drums to get the LBP up front. Sorry, don't remember any details.
       
    • mbaird

      mbaird mbaird

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      At this point it is just a curiosity.
      I was thinking that if I need to get new drums maybe I could just order newer LBP drums if they were interchangeable.
      And when I order new axles I would get LBP in those.

      This turns out not to be the case so I will just stick with the current setup.

      And yes I know how to do the Disc swap... that 68 Fastback has 4 wheel discs...
       
    • Marcohotrod

      Marcohotrod Well-Known Member

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      another option that was done is have the small bolt pattern stuff redrilled to 4.5"
       
    • Jimacuda

      Jimacuda Well-Known Member

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      Then you run into different center register sizes. Not a good idea IMO. You might be able to use an adapter ring, but still...
       
    • mbaird

      mbaird mbaird

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      I will just stick with the 5x4s . Like I said... I will be running steel wheels and dog dishes so its no big deal.
       
    • Marcohotrod

      Marcohotrod Well-Known Member

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      What? I am talking about redrilling all the 4" parts to 4.5" like I did. my aftermarket wheels do not register on the center
       
    • Jimacuda

      Jimacuda Well-Known Member

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      OP said he was going to be using steel wheels.
       
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