67 riviera 3.07 posi

Discussion in 'Got gears?' started by Jukka Haapanen, Jun 10, 2020.

  1. I bought a posi axle a while ago, and been waiting for the motivation to change it to my 67 rivi. The time is here. Im driving quite long distances, and i discovered that the posi i bought is a 3,07, not the 3,42, which is great!
    Are these 3,07 posi diffs rare, or have i been just avoiding them....
    068D67B2-003C-412A-8602-E51AAFDD8EC0.jpeg A212309A-77FF-4110-B0F4-573425D77CB2.jpeg 24A1141B-7F19-4CF7-95C0-12E37ADA1BD4.jpeg
    Table is warped....
     
    SpecialWagon65 likes this.
  2. 1969RIVI

    1969RIVI Well-Known Member

    Both those gear sets are super RARE hard to find especially the 3.42 set. The "big car" 9 3/8 rear end has zero aftermarket support for gears so we're forced to find good used originals. The stock Rivs usually came with the 3.07's and the Riv GS's had the 3.42's.
     
    SpecialWagon65 likes this.
  3. SpecialWagon65

    SpecialWagon65 Ted Nagel

    I see a few more 3.07's but IMHO both rare. Good to see you here Jukka, if you need anything let me know!
    Ted
     
  4. lemmy-67

    lemmy-67 Platinum Level Contributor

    I didn't even know the 9-3/8" posi came in the 3.07 ratio...3.42 is the only one I thought was available in the GS option.
     
  5. 1969RIVI

    1969RIVI Well-Known Member

    3.07 is in standard Riv's the 3.42 came in Riv GS's only.
     
  6. lemmy-67

    lemmy-67 Platinum Level Contributor

    The normal 3.07 rears are non-posi.
     
  7. telriv

    telriv Founders Club Member

    When I bought my '64 Riv. the standard gear was 3.07 I had to order posi.
     
  8. monzaz

    monzaz Jim

    Posi is just an option... Like anything when your building a car you can check off anything ...unless they had power restrictions like big block with radical race cam and a/c option etc.
    Most Penn state cars were posi because of the snow and mountains... so that was always a good place to find posi units back in the day.
     
  9. 1969RIVI

    1969RIVI Well-Known Member

    And Canada:D
     
  10. BQUICK

    BQUICK Gold Level Contributor

    Yeah a Riv with POSI and 4 Blizzacks hard to get stuck.
     
  11. 70rivme

    70rivme Well-Known Member

    My '70 Riv came stock with a non posi 2.78 rear end. I have had luck finding many 3.07 Riv diffs with and without posi. I swapped my diff for a 3.07 posi and this was one of the best upgrades I've done. Now if I can only find a 3.42 to replace the 3.07 I'll be in business.
     
  12. 1969RIVI

    1969RIVI Well-Known Member

    I might be able to help you make that possible, I don't want to clutter this thread so PM me if you'd like.
     
  13. black70buick

    black70buick Well-Known Member

    I don't think the 9 3/8 carriers need anything special to add the basic clutches making them a posi. Dunno, could be wrong. But going from 3.07 to 3.42 makes a world of difference in city driving.
     
  14. monzaz

    monzaz Jim

    Open carrier and Limited slip (posi) carrier are 2 different things. Nothing interchanges in them.
    Just so that is clear.
    You can not just add clutches to an open carrier and voila... you have a posi !

    Jim
    JD Race
     
  15. black70buick

    black70buick Well-Known Member

    If you the OP will permit a slight off topic Q, what is different on the 9 3/8"s to provision for clutches?. I guess I could look at mine, but not interested in getting messy right now.
     
  16. Stage2

    Stage2 Well-Known Member

    3.42 you say... Hmmmmm...
     
  17. 1969RIVI

    1969RIVI Well-Known Member

    I'm working with 70rivme on a deal at the moment if he passes I will let you know.
     
  18. Stage2

    Stage2 Well-Known Member

    I'd rather a 3.23 if one can be found. The one in my parts wagon had been changed, the 3.23 was replaced with a standard 2.78. Phooie!
     
  19. English isnt my first language, so i dont quite get the word ”provision”, but as seen in the pics, the carriers (?) are totally different, thers no way to get the posi things inserted to an open carrier.
     
  20. Is there any chance and any place to get new clutch packs for this posi?
     

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