I need help deciding on gearing

Discussion in 'Engine & Drivetrain' started by Upper tanker, Jul 15, 2017 at 8:55 AM.

  1. Upper tanker

    Upper tanker TYF Newbie

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    Hey all. I just finished a very mild build on my 97 2 door 4x4 tahoe's 350. Pretty much sbe, with all new top end. Anyways, it has 3.42 gearing in it now. I tried to pull a 14ft tandem axle open trailer empty, and it really struggled on the highway. I want to either go with 3.73s or 4.10's in both axles, but I can't make my mind up on what I want. I'm getting about 15 mpg combined give/take, so I wouldn't mind dropping 1-2 mpgs. I would also get rid of the stock "gov-bomb" and go with an aftermarket limited slip. I hate to waste 1k+ on gears and a limited slip unit, only to wish I'd have went with the other option. Anybody have any stories/reason why I should go with one or the other? It has plenty of power when it's not towing anything, but really struggles to stay in OD at 70 with an empty trailer (about 1900 rpms). I will getting the 4l60e rebuilt soon. I beat on this truck a little bit, but I mostly drive it respectable. I just wish it was more towing friendly.
     
  2. bigfootchiro

    bigfootchiro Member

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    What size tires are you running?
     
  3. Upper tanker

    Upper tanker TYF Newbie

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    265/70r16
     
  4. bigfootchiro

    bigfootchiro Member

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    How often do you tow?
     
  5. Upper tanker

    Upper tanker TYF Newbie

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    I have a 19ft camper that I'd like to start towing with my tahoe. I just towed it to a campground this weekend and it felt like an s10 towing a house. I'm really leaning towards the 4.10s, as I've heard the switch from 3.42-3.73 won't be that much of an improvement. On the other hand, I don't like the 2200-2400 rpms on the expressway if I go up north not towing anything. I wish I could get 3.90s in both axles.
     
  6. east302

    east302 Full Access Member

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    What's the weight of that camper?


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  7. Upper tanker

    Upper tanker TYF Newbie

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    Just checked the website, it's only about 3400 lbs (empty).
     
  8. bigfootchiro

    bigfootchiro Member

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    I would think 3.73 axle with your size tires should be sufficient to tow 3500 lbs. If you had larger tires, I wouldn't hesitate on the 4.10. In addition to the gearing, I would consider a tune or an 0411 PCM swap. With a gearing swap and tune, you should have no problems with towing that sucker!
     
  9. Upper tanker

    Upper tanker TYF Newbie

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    It currently has a BB tune on it. I did just email them yesterday though, I feel like it doesn't have the response that it should. I'm almost thinking i will go with the 4.10s and if it's too much, try to step up to 285s and see how that works!
     
  10. bigfootchiro

    bigfootchiro Member

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    That sounds like an even better plan to me. Let me know how the gear change goes. I'm debating on doing mine too.
     

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