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1/2 ton gear ratio (stock)

Discussion in 'The Garage' started by PurePower, Oct 30, 2004.

  1. PurePower

    PurePower Registered Member

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    Could someone tell me what the rear end gear ratio could have been stock from factory on a 1991 Chevy Suburban (cowboy conversion) 4x4 with a 350 engine and auto trans? Thanks
     
  2. southernspeed

    southernspeed 1/2 ton status GMOTM Winner

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    Only way to be sure (apart from drop the cover and count) is put a chalk mard on the tire and one on the prop then drive forward real slow and let a buddy count how many prop revolutions to one tire rev you get (don't run him over...they hate that!)You'll prob have 3.08 or 3.73 i should think.
     
  3. sled_dog

    sled_dog 1 ton status

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    look in the glovebox or on the inner fender well under the hood to find the build sheet. Will probbaly tell your gear ratio. Though it may just say stock ratio. The absolute best way to find out is the remove the diff cover and count the teeth. Never hurts to change the gear fluid anyway.
     
  4. 4xcrazy

    4xcrazy 3/4 ton status

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    I'd be willing to bet either 3.73 or 3.42.

    My '89 came with 3.42 in it.
     
  5. hawk368

    hawk368 Registered Member

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    [ QUOTE ]
    The absolute best way to find out is the remove the diff cover and count the teeth.

    [/ QUOTE ]

    Why do you count the teeth ??? The tooth count it stamped into the ring gear. At least on the stock gears. I've never understood why people count the teeth, when its easier to just find the numbers. Then divide.
     
  6. K5Chris

    K5Chris 1/2 ton status

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    [ QUOTE ]
    look in the glovebox or on the inner fender well under the hood to find the build sheet. Will probbaly tell your gear ratio. Though it may just say stock ratio. The absolute best way to find out is the remove the diff cover and count the teeth. Never hurts to change the gear fluid anyway.

    [/ QUOTE ]

    RPO Ratio
    GM1 2.59:1
    GU2 2.73:1
    HC2 2.76:1
    HE3/G44 3.07:1
    GU4 3.08:1
    GU5 3.23:1
    GU6 3.42:1
    GT4 3.73:1
    GT5/GT8 4.10:1
    HC4 4.56:1

    most likely 3.42, but could be 3.73 or 4.10

    this, however wont show you if they've been changed before.
     
  7. K5MONSTERCHEV

    K5MONSTERCHEV 1/2 ton status

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  8. 3 on the tree

    3 on the tree 1/2 ton status

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    Does the front diff have a little metal tag on it? If the gears have not been changed(?) that will tell you the ratio. My 70 Blazer tag says 41 11 (3.73). Divide big number by little number.
     

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