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Re-gearing a 2013 Silverado 1500 LT

Discussion in 'GM Powertrain' started by Silverback777, Dec 29, 2012.

  1. Silverback777

    Silverback777 New Member

    Hi, I am currently in the process of lifting my 2013 Silverado 1500 LT 5.3 with a Cognito 10-12 Inch lift kit. Set at 12 inch. Balljoint Upper Control Arms, Front cognito Swaybar, Fox/Cognito Coilovers, 8" Deaver Leaf Springs, 3.5" Fabricated Block & Ubolt Kit. 44" Economy Traction Bars, Front CV Driveline. 37x13.50x20 Toyo Open Country M/T Tires on 20x10 BMF Wheels. Stock gears are 3.42, What size gears should I run. I will not be towing anything, mostly just driving around town and some freeway miles. I dont want to loose to much power but I also dont want to run down the freeway at 65 mph tached out. Can somebody please help:great:
  2. Pikey

    Pikey Moderator Staff Member 2 Years ROTM Winner 1000 Posts

    I would suggest at least a 4.56.search google, there are a few calculators that will help out. I ran 38.5" with a 4:56 and turned about 1,100 rpm at 70mph
  3. donyms

    donyms Rockstar 4 Years ROTM Winner 1000 Posts

    Welcome to the club, it's good to have you with us. :glasses:
  4. Conlan Rose

    Conlan Rose Active Member 2 Years 1000 Posts

    :sign0016:to the GMTC
  5. 1953bowtieguy

    1953bowtieguy Member 2 Years 500 Posts

    Welcome to GMTC, hope people here can help you with your lifting:great:
  6. ahmitchell1

    ahmitchell1 Rockstar 4 Years ROTM Winner 1000 Posts

    That's a hell of a lot of lift for a 1500. Might wanna upgrade ur brakes while your at it
  7. Silverback777

    Silverback777 New Member

    Thanks everybody for the welcome and suggestions. As far as brakes go I would like to upgrade, I'll check into it. hopefully not to many $$$$$$$$$$$
  8. seffieldvillage@aol.com

    seffieldvillage@aol.com Rockstar 100 Posts

    Welcome to GMTC!!

    I would agree with Pikey, anything higher than 4.56 and you'll be howling on the freeway!! I would suggest 4.88 as well, I ran those with 6" lift and 35's and it ran like factory.
  9. Silverback777

    Silverback777 New Member

    Yeah I'm thinking 4.88 gears to.
  10. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    Welcome! :great:

    I run 4.56's on my 34" tires and it has me close to stock gearing (I used to have 3.73) with stock tires ... with a mild bias toward power. For 37's you'll want shorter gears than I have ... and 4.88's are what make sense. Your highway fuel milage is going to be atrocious -- plan for that.

    As others have noted you will also want to upgrade your brakes, as your 37" tires will turn less across a given distance than your OEM tires, resulting in less opportunity for your brakes to do their work. Add to that the sheer weight and momentum of those 37's and you will want a big brake kit on all corners ... with at least 4 piston calipers. You'll probably also want cryo-treated rotors since stopping those beastly tires will put out some heat ... and so your rotors need to resist it as well as possible, to avoid warping.

    Also don't forget that this will mean longer brake lines -- which will reduce pedal feel. I strongly recommend stainless steel lines to help restore pedal feel.

    Note:
    I'd be very wary of the temptation to off-road your truck once the mods are done, as your chief weak points are still the the rear diff and axle used for the 1500 ... and the wheels/tires for 37's are some serious weight to turn/move.

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