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Help a noob make up his mind on an axle

Discussion in 'Differential & Driveline' started by hunters628, Jan 15, 2020.

  1. hunters628

    hunters628 Full Access Member

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    Okay Ive been debating on this for a while and am not knowledgeable enough to decide for my self. I have a 1982 K10 that I am building up. I am putting in a 6.2 diesel that im in the process of building and am trying to decide on my axles. Truck is currently 100% stock underneath with a 10 bolt rear with 3.08 gears. I have a set of axles off a 83 K20. Rear is a 14 bolt, not sure if its FF or SF, ill have to check later, with 4.10 gears. Im not sure about either front axles. My plans for the truck are the 6.2 swap, max of a 4in lift, probably 33s, 35s max. Im building this truck to be my daily driver, I drive 200 miles one way on the freeway to visit family very often and a lot of city driving. Im not big into off-roading but would like to drive off-road once in a while to go camping or to a hiking trail. The truck has a SM465 now and in the future, I will swap in a NV4500 for the overdrive. What do you guys think I should do. I was thinking either axle I use I should switch to 3.73 gears, is that a good idea? will a 14 bolt be overkill? Should I sell the 3/4 axles for my use? I just dont know enough about these nitty-gritty things to trust my decision.
    Heres my build thread if anyone is interested. Your comments are appreciated!
    https://www.gmsquarebody.com/threads/82-k10-“shorty”-revival.27685/#post-529181
    Thanks,
    Hunter
     
  2. bucket

    bucket Super Moderator Staff Member

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    Personally, I'd leave the stock 3.08 axles in place. The 6.2 will be much happier with those gears, especially if you drive on the highway a lot. With 33's and mild off roading, they should be ok. The 10 bolt rear doesn't like shock loads and drastic speed changes, that should be minimal with a 6.2 engine. Save the 4.10 geared 3/4 ton axles for when you install the nv4500. That should make for a nice combo.
     
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  3. Craig 85

    Craig 85 Full Access Member

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    I had the same dilemma with my last truck. '79 K15 short bed, 350/350/203. I had 3.08s with a non posi rear. It was cheaper to get 3/4 ton axles (4.10's) for $400 than do the gear swap. The only issue I see is RPM's. My truck was almost pulling 3000 RPM's at 65-70 MPH with 33" tall tires. Your diesel would definitely not like that without an over drive.
     
  4. eskimomann209

    eskimomann209 Supporting Member Supporting Member

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    I agree with the common answer here keep the 3.08 with the SM. When you get the nv4500 put in the 3/4 axles.
    It’s probably a 14ff setup with the 8 lug Dana 44
     
  5. ali_c20

    ali_c20 Full Access Member

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    Same opinion here.
     
  6. hunters628

    hunters628 Full Access Member

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    Thanks for the replies guys! So when I get the NV4500 would I be good to run 4.10s in the 14b or should I change to 3.73? I’ll be running 33s or 35s, haven’t completely decided yet
    Thanks
    Hunter
     
  7. hunters628

    hunters628 Full Access Member

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    Forgot to add, the 1/2 ton rear axle has a “gov bomb” as I’ve heard it called. Does that sway anyone’s decision or is the plan sticking the same?
    Thanks
    Hunter
     
  8. bucket

    bucket Super Moderator Staff Member

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    4.10 will be good with the overdrive trans. If the Gov loc decides to give up, it will just speed up when you want to do the swap, lol. But fresh gear oil that's kept at the proper level will help it last. I suppose you could also disable it so it can't activate and break, if you are concerned with it.
     

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