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More axle code ?'s

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by POWERMAD, Nov 5, 2001.

  1. POWERMAD

    POWERMAD 1/2 ton status

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    More axle code ?\'s

    I found another 3/4 ton it is in an 80 truck and the axle code is G81 standard, From what I can remember isn't that a 3:73 open carrier?
    Before someone says to pop the cover and see, I did not have a chance to, as the owner was not at home.
    TIA


    <font color=green> Too bad ignorance isn't painful </font color=green>
     
  2. HarryH3

    HarryH3 1 ton status Author

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    Re: More axle code ?\'s

    G81 doesn't map to any axle RPO that I know of. Here's the list that I have:

    GU2 = 2.73
    GU4 = 3.08
    GU6 = 3.42
    GT4 = 3.73
    GT5 or GT8 = 4.10
    G80 = Gov-lock


    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
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  3. POWERMAD

    POWERMAD 1/2 ton status

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    Re: More axle code ?\'s

    Thanx Harry.
    That is strange. I wrote down what the code was.
    Hmm maybe he will be home soon I'll just have to take a tarp to lay down as it is in the mud and pop off the cover.


    <font color=green> Too bad ignorance isn't painful </font color=green>
     
  4. POWERMAD

    POWERMAD 1/2 ton status

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    Re: More axle code ?\'s

    I went out and popped the cover and it is a 4:10 open carrier.
    I read the code wrong, after cleaning it off it says GQ1 standard.
    That still doesn't cross whith what you have.

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  5. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    Re: More axle code ?\'s

    In 80 they also had a 3.23 axle.
    I don't know the code (my glovebox and doors aren't original) but I know they are GM because of the GM stamping on the pinion with the part numbers. I kept them when I changed ratios, if I think of it I will dig them out.
    Anyone know what the code is for 3.23?

    See my rig at <a target="_blank" href=http://coloradok5.com/gallery/Leadfoot>http://coloradok5.com/gallery/Leadfoot</a>
     
  6. HarryH3

    HarryH3 1 ton status Author

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    Re: More axle code ?\'s

    <blockquote><font class="small">In reply to:</font><hr>

    I read the code wrong, after cleaning it off it says GQ1 standard.

    <hr></blockquote>
    Where was this number located? Sounds like it came from a tag on the axle. That isn't where the RPO (Regular Production Option) codes are listed. There should be a sticker inside the glovebox or on the inner fender well that lists all of the RPO's that were installed at the factory. That's where you'll find the codes I listed above.

    <font color=black>HarryH3 - '75 K5</font color=black>
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  7. 82K5

    82K5 1/2 ton status

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    Re: More axle code ?\'s

    GQ1 is listed in my '99 RPO book as Axle, Rear, Standard Ratio(Merchandising Option)

    Axle codes are 3 letter combinations. RPO codes have at least one number.



    Phil in Gladstone, MO.
    1982 K5 Silverado Blazer
    Built in Flint, Michigan-January 1982
     
  8. Executioner

    Executioner 1/2 ton status

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    Re: More axle code ?\'s

    Are you sure its 3.23 :1 ? Sounds fishie to me !
    Could you please check on them sometime ?
    Thanks
     
  9. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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    Re: More axle code ?\'s

    Yup, if you look back through my posts (maybe about a year ago) you will see the same. I will get the part numbers though to verify.
    And yes, if someone else had posted this, I would have said there were full of it because I had never heard of 3.23 either (just 3.08 and 3.42). Actually the rear 14 bolt FF was 3.21 and the original front 10 bolt was 3.23. I know these were factory options at one point because the pinions had GM stamped on them near the numbers. This was in 1980 with the slip yoke NP205, Lockup TH350's, etc. It may have been a way to get a little better gas mileage with the 3/4 ton without totally crippling it with 3.08's. Regardless, it's a sucky ratio and probably why it was very uncommon.
    Since then I have heard one other guy in New York who had these same ratios from the factory in a 3/4 ton. I never did ask him what year it was (now I'm kicking myself for not asking) but he had the round headlights so it was pre 81 (if I had to put money on it, I would bet it was an 80 as well).

    See my rig at <a target="_blank" href=http://coloradok5.com/gallery/Leadfoot> click here </a>
     
  10. Leadfoot

    Leadfoot 1/2 ton status Premium Member

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  11. HarryH3

    HarryH3 1 ton status Author

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    Re: More axle code ?\'s

    99? [​IMG] Nothing that new in my driveway... [​IMG]

    <font color=black>HarryH3 - '75 K5</font color=black>
    <a target="_blank" href=http://www.angelfire.com/super/ThunderTruck>www.angelfire.com/super/ThunderTruck</a>
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  12. POWERMAD

    POWERMAD 1/2 ton status

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    Re: More axle code ?\'s

    Harry that was the code that was on the sticker in the glove box.
    For some reason I keep thinking that 3:73 was standard and 4:10 was the option.
    The owner thought it was 3:73 as it is a Trailering special truck. When I told him it was a 4:10 he got a look on his face that seemed to say "damn" I could have gotten more for it.
    He He He


    <font color=green> Too bad ignorance isn't painful </font color=green>
     

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