Rear end gear ratios

Discussion in 'Race car chassis tech' started by Doug Van Kalker, Jan 23, 2003.

  1. Doug Van Kalker

    Doug Van Kalker New Member

    Is there a 3:55 gear ratio available for the 10 bolt rear end?
     
  2. oPh

    oPh Well-Known Member

    Question could be.... which 10 bolt rearend? :puzzled:

    '64-72 Pontiac & 64-67 Buick 8.2 10 bolt offered this ratio & Richmond has version as well ($240 Summit)

    '68 -70 Buick 8.2 10 bolt, ratio jumped from 3.42 to 3.64, no 3.55's.

    8.5 corporate 10 bolt, no 3.55's (3.42 jump to 3.70's & 3.73's)

    8.5 type "O" olds 12 bolt cover 10bolt, no 3.55's

    8.2 Chebby c-clip ten bolt. Did make 3.55's. Richmond still makes them too.

    7.5/7.625 10 bolt ('77 & later) no 3.55's

    Roger
     
  3. flynbuick

    flynbuick Guest

    Doug;

    If you are talking a 70 Buick 8.2 which has the asymmetrical
    carrier bearings the chief engineer for Richmond based in Liberty SC says their 355 does NOT fit. It is my understanding that there is no aftermarket gear for that rear.
     
  4. 70 gsconvt

    70 gsconvt Silver Level contributor

    Right in Summit's catalog is a listing for 8.2 "B" or "P" rearends with a 1.438 pinion stem. They show 3.55, 3.90, and 4.11 gears.

    Items numbers are RMG-4900821 (3.55), RMG-4900841 (3.90), RMG-6903581 (4.11).
     
  5. flynbuick

    flynbuick Guest

    I went through that once too . Summit uses Richmond if a recall correctly. Just call Richmond's home office in Liberty SC and ask to speak with the chief engineer, I cannot recall his name , and he will explain the misconception over what the gears listed in Summit will fit.
     
    Last edited by a moderator: Jan 24, 2003
  6. 73-462GS

    73-462GS GS Mike

    oph- What rear end do I have in a 1972 GS 350 Skylark single legger? I would like to go around 3.55 with a posi. if possible. Thanks. Mike D.
     
  7. flynbuick

    flynbuick Guest

    They changed beginning 71 and I believe you would have an 8.5. The ratio is likely a 2.93, 2.73 or 3.23 if the options are like a 70.
    If it has not been changed the code stamped on the axle housing drivers side can be used. Otherwise you would have to measure the ratio of the turns of the shaft versus the wheels. There is a lot of parts for the 8.5.
     
  8. 73-462GS

    73-462GS GS Mike

    Thank you Jim. Mike D.
     

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