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Got a question before I pick up my 14FF tomorrow

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by MudFrog, Jun 13, 2001.

  1. MudFrog

    MudFrog 1/2 ton status

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    The 14 that I'm getting comes from a 80/81 (I think) C20. The 2wd 3/4 ton truck. It has a 350/465 combo. What is the most common ratio that comes with this combo? I'm assuming 4.10. Did this combo ever come with the 3.73? I'm trying to kind of get an idea of what will be in this rear end. I have not been able to open the cover on it yet.

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  2. thatK30guy

    thatK30guy 1 ton status Premium Member

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    I have no clue. [​IMG]

    It could be a 3.42, 3.73, 4.10, 4.56 or anything else that was swapped in, like, maybe, a 5.13!!!

    Best way to check, take the cover off and look for the stamped numbers on the side of the ring gear.

    <font color=red>I m so we Todd did.
    I m sofa king we Todd did.</font color=red>
     
  3. MudFrog

    MudFrog 1/2 ton status

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    Does the stamp actually show like 3.42, 4.10... yadda yadda yadda?

    89 K5 Silverado
    <A target="_blank" HREF=http://mudfrog.coloradok5.com>http://mudfrog.coloradok5.com</A>
     
  4. thatK30guy

    thatK30guy 1 ton status Premium Member

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    No, it will show a number like '41:11' meaning, you have to divide the 41 by the 11 to get 3.73. A '41:10' would show you 4.10 ratio. Just have to divide the numbers.

    <font color=red>I m so we Todd did.
    I m sofa king we Todd did.</font color=red>
     
  5. turbo

    turbo 1/2 ton status

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    not hard to figure without opening.
    Wiith open diff have someone hold one end(axle) so it cannot turn then slowly turn other axle two complete revolution while counting rotation of pinion.
    If one axle held and other turned two rotations and pinion turns 4 and 1/8 rotations you have a 410 if it went 3.5 you have a 350 ratio ect

    If it is a clutch system with alxes locked together just do one ratation and count pinion the same.

    That is how truck normally works ratio is number of pinion (driveshaft) rotations per one rotation of both axles but if you hold one still you double the speed of the other axle (thus the two turn rule).
     
  6. thatK30guy

    thatK30guy 1 ton status Premium Member

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    Yeah, some have done it that way but its not the most accurate way. The cover off is the best way and only way to get the EXACT info you are looking for.

    BTW, turbo2, nice profile! [​IMG] Hint: fill it out! [​IMG]

    <font color=red>I m so we Todd did.
    I m sofa king we Todd did.</font color=red>
     

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