volare rear end to a-bidy duster

Transmissions and Rear Ends

  1. tkenny

    tkenny New Member

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    Jul 21, 2017
    Hi, I'm new here and have a few questions about two cars I have. ones a volare and in bad shape and the other is a 1974 plymouth duster. I was wondering if it was possible to swap the 8.25 rear end off the volare to the duster as the duster only came with small rear end and small bolt pattern for wheels.
  2. Aspen500

    Aspen500 Well-Known Member

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    Feb 14, 2015
    Rib Mountain (Wausau) WI
    The Volare rear axle is 3" wider than a Duster, which still would work. Duster's always seemed to have a too narrow rear track compared with the front. Also you'll need different spring perches (the pieces welded to the axle tubes). I'm not sure about the spacing between the springs if they are the same or not. The Volare perches have a larger hole (maybe 1" dia?) for the Iso-Mount and you'd need to weld them in and make a hole the size needed for a regular spring center bolt which is much smaller.

    A-bodies could also have the 8.25" rear (my dad's '74 Gold Duster does and it's only a S6/3-speed). Also, A-body with front disc brakes had the 4.5" wheel bolt pattern. Being a '74 I think discs were standard by then(?).
  3. MoparKidD-4

    MoparKidD-4 Well-Known Member

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    Feb 21, 2017
    Fort Collins, CO
    Besides the spring perches it should be a bolt-in deal, all A-bodies made 1973-76 had large bolt pattern 5 x 4.5" setup so whatever wheels you have on the Duster now will bolt right back on. I have a 1970 Duster I upgraded to 1973-up front discs and an 8 3/4" rear out of a late-60s B-body, that car originally had the small bolt pattern 5 x 4".
  4. BudW

    BudW Moderator Staff Member

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    Mar 4, 2012
    Oklahoma City
    You have me wondering: you have a ’74 Duster with small bolt pattern wheels?

    From the early ‘60’s, there were 5 different A-body differentials used:
    ’63-72 7¼” 53.20” flange to flange (backing plate to backing plate) (small bolt pattern)
    ’66-71 8¾” 52.23” flange to flange (small bolt pattern)
    ’72 8¾” 52.578” flange to flange (big bolt pattern?)
    ’73-76 7¼” 51.40” flange to flange (big bolt pattern)
    ’73-76 8¼” 51.40” flange to flange (big bolt pattern)
    All A-body differentials are 43” perch center to perch center.

    FMJ differentials are all 54.340” flange to flange. 44.46” perch center to perch center.
    The perches will need to be cut off and replaced or re-welded on.

    FMJ perches have a larger center hole – so if going into an A-body, then use perches with the smaller holes when re-welding them on (new ones can be bought fairly cheap).

    Also note: the 7¼” shock plates will be different – so one will need to find either 8¼” or 8¾” shock plates, as well.