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never heard of this

Discussion in 'The Garage' started by poolcues, Mar 26, 2005.

  1. poolcues

    poolcues 1/2 ton status

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    i found some axles from an 83 k20 to do a swap so when i asked the guy to crack the diff cover before i drove 4 hrs to get them he told me they had 3.42's:confused: i've never heard of this.i always thought they ran at least 3.73's in a k20.anyone else heard of this.i'm wondering if the guy counted the teeth on the pinion gear wrong.
     
  2. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    my 83 k20 has 3.42s from the factory, depends on the GVW of the truck i think. (mines a light 3/4 ton)
     
  3. R72K5

    R72K5 Banned

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    3.21, 3.42, 3.73

    3.42 is more common in 80s k20

    i dunno where yhou leanred that 3.73 is what they used

    4.10 is 14 FF 10.5 ratio

    you have research to do lol


    good luck
     
  4. bablazer73

    bablazer73 1/2 ton status

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    I've had a couple with 3.42's. But usually only in the light duty 3/4 tons. Which also use the 14 bolt semi floater axel. I have never seen a Full floater with 3.42's. but GM did do alot of stupid stuff.
     
  5. R72K5

    R72K5 Banned

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    the C6P HD chassis equipment optionthat was available in the early/mid '80s K20s got ya 3.42 SF 14 all the time, seen many such rigs with the 5.7L and 465 i even owned one of them last year,

    see them around, very common


    and i guess i may be wrong but i coulda swore chevy showed 3.42 in the FF axles too, hmm.. ill have to find my 81 book, i couldnt find 3.42 in the 73 one, hum,.. i stand corrected if really was no 3.21 in the FF axles, hard to remember/keep track of certain little things sometimes, hummmm, epsecially when you always force yourself to learn more and more and more for years and years

    but 14 FF did have 3.21, 3.73, 4.10, 4.56 though, most all years, 3.73 and 4.10 are the very most common FF ratios, by FAR



    good luck
     
    Last edited: Mar 27, 2005
  6. u2slow

    u2slow 1/2 ton status

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    3.21/3.42 are usually found in BBC C20s with the 14FF. 3.21 for the 70's... 3.42 for the 80's.
    Even came across a 94ish 2wd 1-ton reg cab LWB with 5.7L & 3.42 :confused:
     
  7. poolcues

    poolcues 1/2 ton status

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    this one is an 83 k20 with with a diesel/sm465/205-10 bolt/14 ff and that's the thing confusing me the most.i knew 3.42's were common in the sf's but not the ff's and running a diesel.oh well i guess i need to get to reading a little more!! LOL
     
  8. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    if its factory stuff, it has a sm465/np208 and a sf rear, only the BBC trucks got a FF in 81 and newer (3/4 ton) and you can only get a BBC in a 2wd. but it could have been swaped easily.
     
  9. 82K5_6.5L

    82K5_6.5L 1/2 ton status

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    my 82 K5 came with the 10 bolts f/r w/ 3.42's.. im lookin at the little Service Parts Identification card that is on the glove box
    "Option No. 1GU6 Rear Axle - 3.42 RAT"

    this is kinda crazy, cuz reading what everybody was sayin that they came in the 3/4 tons, but my K5 is just 1/2 ton that came with a 6.2, 700r, 208 and 10 bolts...

    crazy ass GM :D
     
  10. atho

    atho 1/2 ton status

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    its just a gear ratio...it doesnt matter what series it came in. :confused:
     

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