Have 3:73 - should I go with 4:11 or 4:56 from your experience

Discussion in 'GM Powertrain' started by MY2002GMC, Dec 29, 2011.

  1. MY2002GMC

    MY2002GMC New Member

    Hi guys - I have a 2002 GMC Sierra extcab automatic with 4.8 and 3:73 gears and is lowered. Have headers, electric fan, cold air and street tune. I am having a B&M Megashifter being installed and a Transgo HD Reprogramming Shiftkit. I am hesitant to have a stall put on it, but would like to consider bumping up the gear ratio to 4:11 or 4:56 for addl low end response. I do take it on trips occasionally about 1,000 miles from Pensacola to NC and back (why no stall yet). No taking to the strips yet; but like street performance. If you guys have smiliar experience and want to share ++++'s and/or -----'s, please do. I am not so sure if it makes that much difference to go higher (4:56) if I am going into the 4's anyway, but share your thoughts. thx.
  2. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I don't know that the change from 3.73's to 4.11's is enough to justify the cost...
  3. MY2002GMC

    MY2002GMC New Member

    Good point surrealone. Also forgot having a TCI HD Servo installed. I also think that I can adjust my MPH speed on the interstates; i.e., if I was cruising at 72 I can lower the cruise to 62 and should not have that much impact on mileage?--- From what I heard, major gas impact is the speed over 50 MPH is wind resistance - 1.5 MPG for each 5 mph over. Should not be too much difference in town unless my lead foot takes over ::)
  4. ntbush83

    ntbush83 Epic Member 5+ Years ROTM Winner 1000 Posts

    This is kinda trick because I don't know to many people running more than stock gearing unless they are drag racing or running 35'' plus tires. I have 4:10 gears and can't say my acceleration is that great but then again I'm running 33's. So you might notice a difference with the 4:11's with a smaller tire and still keep decent mileage.
  5. tbplus10

    tbplus10 Epic Member Staff Member 5+ Years 5000 Posts Platinum Contributor

    As others said this is a trickey question to answer, if your gonna change the gears you definantly want to go 4.56.
    3.73 to 4.11 isnt really noticeable.
    From what I understand your truck has factory or close to factory size tires, so while you'll see a big difference in low end your gonna lose top end performance and MPG.
    I would probably stick with 3.73's if my truck was serving multi purpose like yours, the loss of mileage will add up if you take to many trips. Not just the mileage but the additional wear and tear on the drive train running higher RPMs on the highway will add up too.
    I'd look at the stall convertor before I looked at gearing in this situation.
    If you had larger tires or used the truck only for in town running around it wouldnt be a problem.
  6. MY2002GMC

    MY2002GMC New Member

    Thanks guys for the info so far - I will think some more before I jump into anything. Any others are welcome to respond.

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