An accurate 8 3/4" rear axle width list

Transmission and Drivetrain Tech

  1. 72bluNblu

    72bluNblu FABO Gold Member FABO Gold Member

    Messages:
    11,566
    Likes Received:
    6251
    Joined:
    Nov 28, 2008
    Location:
    NorCal
    Local Time:
    2:35 AM
    Ok, so, I've posted parts of this list a few times, normally in response to some of the really inaccurate charts and lists that are out there and posted too frequently. It's not my list, I sourced it from the internet but I can't remember where. Since the time I downloaded it several years ago, I have personally confirmed a bunch of these numbers. The A-body numbers, the E-body numbers, several of the B-body measurements, a couple of the C-body measurements, and even the D100 measurements. They've all been spot on, so I have no reason to suspect any of the measurements I haven't personally checked.

    Everything is for 8 3/4 axles with the exception of the A-body 8.25 and BBP 7.25 measurements I added myself, and the F-body 8.25" measurements.

    I also added the A-body BBP 8 3/4 width, that's for an A-body housing with axles that have the standard BBP axle flange offset and use 10x2.5" or 11x2.5" BBP brakes. It should be accurate within an 1/8".

    8 3/4" Housing widths, flange to flange

    A-BODY
    • '66-'72= 52 5/8”
      • BBP 7.25/8.25 = 51.5”
    B-BODY
    • '62-'63= 53 1/4" (And '64 Max Wedge)
    • '64 = 55 5/8" (Exc. Max Wedge)
    • '65-'67= 54 1/4"
    • '68-'70= 54 15/16"
    • '71-'74= 57 7/8"
    • '71-'73 wagon= 59 7/16"
    C-BODY
    • '65-'69= 56 3/4"
    • '70-'71= 57 7/8" (Chrysler & Fury)
    • '70-'74= 59 7/16" (and '69 wagon)
    IMPERIAL
    • '65-'66= 57"
    • '67-'69= 57 3/8"
    • '70-'71= 54 3/4"
    • '72-'73= 59 5/8"
    E-BODY
    • '70-'74= 56 31/64"
    A100
    • '65-'70= 56 3/4"
    D100
    • '65-'71= 58 5/16"
    • '72-'74= 59 7/16"
    F-BODY (8.25" axle!)
    • ’76-’80= 54.34”
    .........................................
    ........................................

    8 3/4" Rear end widths, drum-to-drum:

    A-BODY
    • '66-'72= 57 1/8” (or 57 13/16” for BBP axles and brakes)
      • BBP 8.25/7.25= 56 3/4”
    B-BODY
    • '62-'63= 58 1/2" (And '64 Max Wedge)
    • '64 = 60 7/8" (Exc.Max Wedge)
    • '65-'67= 59 1/2"
    • '68-'70= 60 1/8"
    • '71-'74= 63"
    • '71-'73 wagon= 64 3/8"
    C-BODY
    • '65-'69= 61.75"
    • '70-'71= 63.0" (Chrysler & Fury)
    • '70-'73= 64 3/8" (and '69 wagon)
    IMPERIAL
    • '65-'66= 61 15/16"
    • '67-'69= 62 5/16"
    • '70-'71= 59 3/4"
    • '72-'73= 64 9/16"
    E-BODY
    • '70-'74= 61 5/8"
    A100
    • '65-'70= 61 3/4"
    D100
    • '65-'71= 63 15/16"
    • '72-'74= 64 3/8"
    ........................................
    ........................................

    Spring perch widths (center-to-center)

    A-BODY
    • '66-73= 43"
    B-BODY
    • '62-'70= 44"
    • '71-'74= 47.3"
    C-BODY
    • '65-'73= 46"
    E-BODY
    • '70-'74= 46"
    F-BODY (8.25" axle!)
    • ’76-’80= 44.5”
     
    Last edited: Nov 19, 2016
    • Like Like x 11
    • Thanks! Thanks! x 1
    • 72bluNblu

      72bluNblu FABO Gold Member FABO Gold Member

      Messages:
      11,566
      Likes Received:
      6251
      Joined:
      Nov 28, 2008
      Location:
      NorCal
      Local Time:
      2:35 AM
      Here's some actual axle lengths as well

      8 3/4" axle shaft lengths (measured from the tip of the splined end to the outside of the flange)

      A-BODY
      • '66-'72= 27 11/16"
      B-BODY
      • '65-'67= 28 7/8"
      • '68-'70= 29 3/16"
      • '71-'74= 30 5/8"
      • '71-'73 wagon= 31 21/64"
      C-BODY
      • '65-'69= 30"
      • '70-'71= 30 5/8" (Chrysler & Fury)
      • '70-'73= 31 21/64" (and '69 wagon)
      IMPERIAL (Large Bolt Pattern)
      • '65-'66= 30 1/8"
      • '67-'69= 30 5/16"
      • '70-'71= 29"
      • '72-'73= 31 7/16"
      E-BODY
      • '70-'74= 29 31/32"
      A100
      • '65-'70= 30"
      D100
      • '65-'71= 31 1/8"
      • '72-'74= 31 21/64
       
      • Like Like x 2
      • Thanks! Thanks! x 1
      • abodyjoe

        abodyjoe Well-Known Member

        Messages:
        21,640
        Likes Received:
        7421
        Joined:
        May 22, 2004
        Location:
        Berlin,N.J. 08009
        Local Time:
        5:35 AM
      • Dartnut

        Dartnut Don't hate me because i'm beautiful

        Messages:
        11,468
        Likes Received:
        4184
        Joined:
        Apr 19, 2007
        Location:
        Southern Alberta
        Local Time:
        3:35 AM
        This should be made into a sticky.
         
        • Like Like x 1
        • 72bluNblu

          72bluNblu FABO Gold Member FABO Gold Member

          Messages:
          11,566
          Likes Received:
          6251
          Joined:
          Nov 28, 2008
          Location:
          NorCal
          Local Time:
          2:35 AM
          That's where it came from! Still, it seems like every other day someone posts one of those incorrect charts. Glad it's been stickied here.

          It has! :D
           
          • Agree Agree x 1
          • abodyjoe

            abodyjoe Well-Known Member

            Messages:
            21,640
            Likes Received:
            7421
            Joined:
            May 22, 2004
            Location:
            Berlin,N.J. 08009
            Local Time:
            5:35 AM
            yea i know.. they keep regurgitating that garbage chart..
             
          • MyPlumCrazy

            MyPlumCrazy Active Member

            Messages:
            25
            Likes Received:
            1
            Joined:
            Jun 18, 2015
            Location:
            Hurley
            Local Time:
            5:35 AM
            Does any body have any charts for the axle spline count. Trying to see if a 741 center from a 71 charger will be an easy swap into my 71 duster.
             
          • Alaskan_TA

            Alaskan_TA Well-Known Member

            Messages:
            5,930
            Likes Received:
            4329
            Joined:
            Nov 12, 2004
            Location:
            PA
            Local Time:
            5:35 AM
            The centers are a direct swap with the same spline count. (if both rear ends are 8 3/4" of course).
             
          • MyPlumCrazy

            MyPlumCrazy Active Member

            Messages:
            25
            Likes Received:
            1
            Joined:
            Jun 18, 2015
            Location:
            Hurley
            Local Time:
            5:35 AM

            Yes but does any body know if the 71 duster and 71 charger share the same spline count.
             
          • 72bluNblu

            72bluNblu FABO Gold Member FABO Gold Member

            Messages:
            11,566
            Likes Received:
            6251
            Joined:
            Nov 28, 2008
            Location:
            NorCal
            Local Time:
            2:35 AM
            As far as I know, all of the OE 8 3/4 3rd members have the same spline count. Now, if it was an aftermarket set up for drag racing it might be different. But I've never seen anything that said to even check the number of splines on an OE 8 3/4 3rd member to see if the spline count was the same as the OE one it was being swapped with.
             
          • Alaskan_TA

            Alaskan_TA Well-Known Member

            Messages:
            5,930
            Likes Received:
            4329
            Joined:
            Nov 12, 2004
            Location:
            PA
            Local Time:
            5:35 AM
            One more time then. ;-)

            I have swapped several over the years from A, B, & C bodies & 1/2 ton trucks & vans also. The stock axle splines are all the same regardless of 741, 742 or 489 case.
             
            • Thanks! Thanks! x 1
            • MyPlumCrazy

              MyPlumCrazy Active Member

              Messages:
              25
              Likes Received:
              1
              Joined:
              Jun 18, 2015
              Location:
              Hurley
              Local Time:
              5:35 AM
              Awesome... Thank you everyone.
               
            • fishy68

              fishy68 Tyr Fryr's Inc. FABO Gold Member

              Messages:
              16,956
              Likes Received:
              951
              Joined:
              Jan 11, 2005
              Location:
              Central, IL (Hooterville)
              Local Time:
              4:35 AM
              This is correct. I've taken several 8-3/4's apart all the way from an early 60's unit to early 70's units (open's and sure-grips) and they all had 30 spline axles. Only aftermarket stuff is different.
               
              • Agree Agree x 1
              • retroron

                retroron FABO Gold Member FABO Gold Member

                Messages:
                881
                Likes Received:
                716
                Joined:
                Apr 9, 2014
                Location:
                Livermore Calif
                Local Time:
                2:35 AM
                blunblu A bit off of the subject, where do you get your rear end oil seals? Stock A body 8 3/4 489 case.
                 
              • 72bluNblu

                72bluNblu FABO Gold Member FABO Gold Member

                Messages:
                11,566
                Likes Received:
                6251
                Joined:
                Nov 28, 2008
                Location:
                NorCal
                Local Time:
                2:35 AM
                I get all that stuff from Cass at DoctorDiff Drivetrain Components
                 
                • Agree Agree x 1
                • retroron

                  retroron FABO Gold Member FABO Gold Member

                  Messages:
                  881
                  Likes Received:
                  716
                  Joined:
                  Apr 9, 2014
                  Location:
                  Livermore Calif
                  Local Time:
                  2:35 AM
                  Thanks, I couldn't remember the company's name
                   
                • abodyjoe

                  abodyjoe Well-Known Member

                  Messages:
                  21,640
                  Likes Received:
                  7421
                  Joined:
                  May 22, 2004
                  Location:
                  Berlin,N.J. 08009
                  Local Time:
                  5:35 AM
                  yea dr diff is a great source.. good price too.
                   
                  • Agree Agree x 2
                  • Krooser

                    Krooser Reform School Graduate

                    Messages:
                    3,033
                    Likes Received:
                    2559
                    Joined:
                    Jul 19, 2015
                    Location:
                    Central Wisconsin
                    Local Time:
                    4:35 AM
                    Any parts store should have axle and pinion seals....walk in with cash walk out with parts.
                     
                    • Like Like x 1
                    • cosgig

                      cosgig MoBro Inc. FABO Gold Member

                      Messages:
                      11,599
                      Likes Received:
                      4794
                      Joined:
                      Jul 20, 2008
                      Location:
                      Pinckney, Michigan
                      Local Time:
                      4:35 AM
                      Glad to see this made it to sticky status! You're right blunblu, seems that every other day someone is looking for the correct information, and someone always chimes in with that old incorrect chart!
                       
                      • Agree Agree x 1
                      • winstoninwisc

                        winstoninwisc Taint easy livin free,season ticket ona 1wayride

                        Messages:
                        2,333
                        Likes Received:
                        113
                        Joined:
                        Aug 1, 2012
                        Location:
                        sun prairie wi.
                        Local Time:
                        3:35 AM
                        Gr8 post
                         
                      • Cuda416

                        Cuda416 FABO Gold Member FABO Gold Member

                        Messages:
                        1,568
                        Likes Received:
                        1059
                        Joined:
                        Jun 12, 2014
                        Location:
                        South, TX
                        Local Time:
                        3:35 AM
                        A-BODY
                        • '66-'72= 52 5/8”
                          • BBP 7.25/8.25 = 51.5”
                        Safe to assume 63-65 fall into this range as well?
                         
                      • Zcuda68

                        Zcuda68 Well-Known Member

                        Messages:
                        62
                        Likes Received:
                        9
                        Joined:
                        Feb 20, 2017
                        Location:
                        Washington
                        Local Time:
                        2:35 AM
                        I have a slant six car and am changing to v8 car with 8.75. 8.75 "A body" rear end is currently sbp, changing to bbp. I'm trying to figure out backspacing for wheel without converting to bbp and disc setup and the having to possibly cut axle down. I want to run 6.38 BS. Car is completely torn down, going to mini tub and cut lip of rear quarter and possibly roll. Also have 3/4" shackle offset. Want to run a 295/40r18. Any help would be appreciated
                         
                      • 72bluNblu

                        72bluNblu FABO Gold Member FABO Gold Member

                        Messages:
                        11,566
                        Likes Received:
                        6251
                        Joined:
                        Nov 28, 2008
                        Location:
                        NorCal
                        Local Time:
                        2:35 AM
                        So, is this for a '68 Barracuda like your screen name would suggest?

                        If it is, you're basically going to be running the same set up as I am with my Duster, except with a BBP A-body 8 3/4 in place of the B-body 8 3/4 I run. Assuming you're looking at an 18x10 for a rim, it's just correcting for the axle width change because the wheel houses are pretty much the same and we both have offset springs. The 18x10's I run have a 7" backspace, but I run them with drums at the moment. The B-body 8 3/4 I run puts the wheels out about 1.15" further than a BBP A body 8 3/4, so, you'd be looking at 5.85" of backspace to put the tires in the same spot. Most disk kits add 5/16" to 3/8" per side for width, so, add that in and figure about 6.15"- 6.22" depending on the disk kit.

                        Which means 6.38" is pretty darn close. More than likely you'll need a small wheel spacer to make it work, you'd be looking at about a 1/4" spacer. But that's assuming everything is identically the same, which is won't be. Bottom line is you'll have to measure your own car, but an 18x10 with 6.38" of backspace with the offset springs and a quarter lip trim should be in the ballpark with 295/40/18's with a BBP A-body 8 3/4 with rear disks if you run some kind of small spacer.

                        295/40/18's are about as tight a fit as you can make it, so, you will definitely need to make your own measurements and plan on making some adjustments to get the clearance you need. Feel free to send me a message if you want so we don't sidetrack this thread.
                         
                        • Like Like x 1
                        • 1969moparDART

                          1969moparDART Well-Known Member

                          Messages:
                          215
                          Likes Received:
                          31
                          Joined:
                          May 15, 2018
                          Location:
                          texas
                          Local Time:
                          4:35 AM
                          i just ahve a quick question, can a 8 3/4 from a 66 dodge charger be made to fit my 1969 dodge dart? i know the springs need to be relocated but im cool with that but will i need to have the housings cut?
                           
                        • 72bluNblu

                          72bluNblu FABO Gold Member FABO Gold Member

                          Messages:
                          11,566
                          Likes Received:
                          6251
                          Joined:
                          Nov 28, 2008
                          Location:
                          NorCal
                          Local Time:
                          2:35 AM
                          You don’t necessarily NEED to cut the housing. That rear axle will add a little less than 7/8 to each side for backspace compared to an A-body 8 3/4 with BBP axles. So, for example, a 15x7 with 4.25” of backspace isn’t s bad choice for a BBP a body 8 3/4, but to keep the wheel in the same place with the 66 B body a 15x7 would need 5 1/8” of backspace. That’s doable, but it would probably be a custom rim in a 15” diameter. In a 17” rim it’d be a piece of cake.

                          Just depends on what you’re doing.
                           
                        1. This site uses cookies to help personalize content, tailor your experience and to keep you logged in if you register.
                          By continuing to use this site, you are consenting to our use of cookies.