which 4 speed correct for 72 GS455?

Discussion in 'U-shift em' started by HOOSIER67, Oct 8, 2007.

  1. HOOSIER67

    HOOSIER67 Well-Known Member

    Help!

    I'm in the process of buying a 72 GS455 4 speed car that is missing its original tranny. Can anyone tell me which transmission would have come in it? I'm not sure if it should be a Muncie, a Saginaw, or what:Do No:

    Thanks
    Rob
     
    HOOSIER67, Oct 8, 2007
    #1
  2. flynbuick

    flynbuick Guest

    Muncie
     
    flynbuick, Oct 8, 2007
    #2
  3. HOOSIER67

    HOOSIER67 Well-Known Member

    Jim,

    Thanks for the info. Which Muncie? M20???
     
    HOOSIER67, Oct 8, 2007
    #3
  4. TXGS

    TXGS Paint by numbers 70 GS 455 4spd

    M21 :beer
     
    TXGS, Oct 8, 2007
    #4
  5. HOOSIER67

    HOOSIER67 Well-Known Member

    Thanks Phil!!:beer :TU:
     
    HOOSIER67, Oct 8, 2007
    #5
  6. Brett Slater

    Brett Slater Super Moderator Staff Member

    Phil,

    My car came with the M20 and I thought I had heard a while back that it was the standard 4-speed on these cars....

    Of course, I could be wrong...that usually happens about 25-30 times a day...

    Here's my window sticker as a reference:

    [​IMG]
     
    Brett Slater, Oct 9, 2007
    #6
  7. Sturmgewehr

    Sturmgewehr Well-Known Member

    Brett --I thought that "M20" code on the window sticker does NOT mean
    an M20 tranny. Did I read that on this board? If I'm wrong sorry:spank:
    Pete
     
    Sturmgewehr, Oct 9, 2007
    #7
  8. Brett Slater

    Brett Slater Super Moderator Staff Member

    Pete,

    As stated in my reply, there's a good possibility I could be wrong....

    :confused:
     
    Brett Slater, Oct 9, 2007
    #8
  9. Davis

    Davis Moderator

    Marco stated in another thread "All the Buick 4-speed transmissions I've decoded for the registry have been M-21s."

    The RPO code for a manual trans 4 speed is RPO M20

    confusing isnt it :3gears:
     
    Davis, Oct 9, 2007
    #9
  10. flynbuick

    flynbuick Guest

    You are correct M20 is the RPO code for the M21 Muncie.
     
    flynbuick, Oct 9, 2007
    #10
  11. bignastyGS

    bignastyGS Maggot pilot

    That's about to change this weekend.I have an M20 I put in my 73 4 speed GS car from a 68 GS400. I can tell a whopping difference in the car compared to when it had the M21 in it..
     
    bignastyGS, Oct 9, 2007
    #11
  12. Rich Johns

    Rich Johns Platinum Level Contributor

    Yes it is confusing.
    Buick listed M20 as 4 speed trans as (Option order Number) however it gave you a close ratio M21 muncie 4 speed.
     
    Rich Johns, Oct 10, 2007
    #12
  13. gstewart

    gstewart Well-Known Member

    could an m22 be special ordered for the 1970 a-body buicks?
     
    gstewart, Oct 12, 2007
    #13
  14. Duane

    Duane Member

    Not that I am aware of.
    Duane
     
    Duane, Oct 12, 2007
    #14
  15. Lee Bacon

    Lee Bacon Well-Known Member

    Hi Pat, what kind of difference? Thank's
     
    Lee Bacon, Nov 10, 2007
    #15

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