Posi Differential Donor Options?

Discussion in 'Transmission & Driveline Topics' started by MMFS, Oct 9, 2019.

  1. MMFS

    MMFS New Member Gold Member

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    Mostly 80s and early 90s domestic cars and trucks... I do have a 1970 Monte Carlo, a 1963 Mercury Comet and a 1974 Mercury Comet convertible...
     
  2. big gear head

    big gear head Veteran Member

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    Does the Monte have a 12 bolt in it?
     
  3. MMFS

    MMFS New Member Gold Member

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    Probably, I’ll have to go look...
     
  4. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

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    Freddie, could there be odd ball S10s with a posi that would work?

    Or g body i suppose, but that rear is too valuable to take the posi
     
  5. big gear head

    big gear head Veteran Member

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    All of the S series trucks that had a limited slip differential got the Governor Lock, same as the full size. Yes, the Buick GN and T Type got the same Traction Lock as the Camaro, but as you said, you wouldn't want to split up one of those.
     
  6. BonzoHansen

    BonzoHansen Administrator Lifetime Gold Member

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    Some odd ball olds to i think. 442s?

    So trucks and s10 are 8.6s?
     
  7. MMFS

    MMFS New Member Gold Member

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    There are a few S10s down there; closest thing I found was a 1987 Caprice Brougham, but it’s not the police package; there may be one of those, but didn’t see it/can’t get to it... There are 3 Ford Police Interceptors that I can see...
     
  8. Gary S

    Gary S Administrator Lifetime Gold Member

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    That '87 Caprice most likely will have a 7.5" rear end in it. Most of the "civilian" models of Caprice and Impala after 1977 have 7.5" rears unless they had posi. My Son has a '77 Impala that came with a 8.5 non-posi, but all the later ones I've had were 7.5". Police and Taxi versions had the heavier duty 8.5" and also were more likely to have posi. A few years ago before the Cash for Clunkers disaster, I found a '79 Caprice in the junk yard with a 8.5" posi, and my Son found another one from a "76 Monte Carlo which ended up in his '77 Impala where it now lives.
     
  9. big gear head

    big gear head Veteran Member

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    Most of the S10 rear ends are 7.5, but a few in the '90s and early 2000s got the 8.5/8.6 rear end. All of the truck (S series and full size) 8.5 and 8.6 limited slip differentials were the Governor Lock, which is a bad idea for a performance car. They were barely good enough for a stock truck.

    Yes, there were a few 442s in the 80s that got the 8.5, but they were rare.
     
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