3.73 to 4.10s?

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by metalsystem761, May 14, 2012.

  1. metalsystem761

    metalsystem761 New Member

    ok I have an 07 crew cab LTZ silverado with 3.73s 4speed just put 22s on it and after awhile its sluggish to me and was wondering if 4.10s is worth it?

    I've see prices from 120-200 and not a problem I just trying to get an idea and u believe its a 10 bolt if im wrong.
  2. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I just regeared from 3.73's to 4.56's and it was a little under 1500 for the parts (Nitro gears), labor, and tax. Bear in mind I have a 4x4 (also a 10-bolt), so I had to do work both front and rear. You should expect about half that in costs for parts/labor if your truck is 2WD.

    As for whether or not it's worth it ... it depends. Your 22's are adding weight but what about your tires? What's the diameter, there? I ask because the bigger they are the more they weigh, as well, and the more power you need to get/keep them moving. This becomes relevant to MPG's when on inclines, as with proper gearing you can remain in overdrive whereas with longer gears you'll need to downshift to maintain speed.

    Here's a page that should help you: http://www.omix-ada.com/gear-ratio-vs-tire-size.asp. Pay particular attention to the chart -- it can be used as a rough (key word: rough) guide. For more precise calculations this page should help: http://www.4lo.com/calc/gearratio.php


    P.S. Keep in mind there's no right/wrong answer, here. I was wavering between 4.10's and 4.56's and went with 4.56's because I only do about 1/3 of my driving on the highway and I DO off-road with my truck (trails, fields, occasional logging roads, etc), so I leaned a bit more toward power for my 34.3" tires.
    Last edited: May 14, 2012
  3. metalsystem761

    metalsystem761 New Member

    the tires are 305/40R22 and yes 2wd I hear people say the gas isn't too much different . but I know the rims and tires weight it down compared to my old 20s
  4. aloxdaddy99

    aloxdaddy99 Epic Member 5+ Years 1000 Posts

    X2 on what Sur said. If you kept the over all diameter the same as what you had before than your mind may be playing games with you. But if you increased the over all diameter than a gear change may be the key. What size change? Depends on how big of a change.
  5. metalsystem761

    metalsystem761 New Member

    I believe the 20s were 275/55/20
  6. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    Ok, so 275/55R20's translate to a diameter of 31.9"

    And 305/40R22's translate to a diamete of 31.6"

    Here's the calculator I used: http://www.miata.net/garage/tirecalc.html

    It would seem you picked up some rim weight but you lost some tire weight (in the form of 1/3" of height, due to the profile difference, I'm sure). You shouldn't be substantially more sluggish after the change unless those rims are made of lead and the tires of feathers. I exaggerated for effect, there, but you get the idea.

    That said, your 3.73's were intended for OEM rims and wheels. What were the OEM sizes (wheels and tires) with which the truck came from the factory to the dealership? That's probably a better starting point. (This means if you bought it from the dealership with bigger wheels/tires you need to find out what it had before the dealership changed things.)
  7. metalsystem761

    metalsystem761 New Member

    they actually came with after market 20s when I got it new.
  8. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    I doubt the manufacturer shipped it to the dealer with aftermarket (key word 'aftermarket' ... i.e. not OEM) 20's. What did it have on it when it arrived at the dealership? That's the million dollar question, as that's what it was properly geared for...
    Last edited: May 14, 2012
  9. metalsystem761

    metalsystem761 New Member

    Idk this one was a demo and they had put aftermarket rims on it and brought it to the dealership and it caught my eye
  10. SurrealOne

    SurrealOne Former Member ROTM Winner 1000 Posts

    What's the sticker in the driver's side door jamb say? There's usually wheel/tire data there. It's only relevant to get an idea for how far out of spec you are, really. i.e. The data's not essential.

    As for your sluggishness, based on the calculations, below, Aloxdaddy99 hit the nail on the head; it's probably, by and large, a perception issue on your part. Based on the current wheel/tire info, though, it looks like you're at 31.6", which we'll round to 32" for estimating purposes. Applying that to the following chart shows 4.10's to be the low side of best performance with 4.2x's being the next step up.


    If you're done changing tire sizes and have settled on one, then it's time to regear and 4.10's are a solid choice.
    Last edited: May 14, 2012

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