I have a 2012 Chevrolet 2500HD 6.0 WT 4x4 crew cab with 3.73 gears. I use it to tow a camper that weighs aprox 9k lbs loaded. My truck pulls this fine, but I will say going up medium grades or more...I'm not impressed. I know, I should have got a Diesel, but they were out of my price range at the time. I have read some about peeps swapping to 4.10 gears, reviews are mixed. I realize I would be loosing some gas mileage by doing this, but as long as there is an increased ease of towing, that is my goal. Some advise it would be easier on the transmission to switch to 4.10 also. Just curious on ya'lls thoughts or advice. I plan to keep my truck, I like it, just trying to get it to tow a little(or a lot) better. I do use the tow haul when towing, and I understand that part of that process is keeping the trans from shifting so much, but it seems at times my tac goes pretty high climbing those HWY hills and I find myself letting out of it and then I'm stuck putin at maybe 50mph in a 70mph, loaded semi'* and everyone else flying past me =/

You might do better by installing a heavy duty cooler for the transmission.

CathedralCub'* summary: 3.73 to 4.10 is a bit less than a 10% improvement. It won't make that big of a difference, plus: you'd have to re-gear both differentials while you're at it.

The long version: I'm assuming you have a 6L80/6L90 transmission. The old 4L80 (and THM400) had a relatively tall first gear at 2.48:1 . Your 6L80/6L90 starts at 4.027:1 and lots more gears in between. Going from a 3.73:1 to a 4.10:1 is only a 10% difference. It might keep you in a particular gear a little longer, or give you a few MPH climbing a hill, but the Semi'* and the turbodiesels will still go by at about the same rate. One more thing to think about: As you climb, the air gets thinner for your engine. As the turbodiesels and the Ecoboosts climb, the air doesn't get much thinner for them. You could change to a 10:1 gear ratio and still not overcome this . . . you'd just end up in a higher gear at about the same speed with the same experience.

Ty for the detailed info! No way I'd put the $$ if it'* only 10% possible gain. Guess I'm stuck slugging it with the gas burner unless someone knows of another viable option. It'* a shame too, I'm not that close to the towing capacity to be so restricted feeling.

Yeah. Fixing this would be expensive. If you improve the breathing that would be less expensive and would help a little.

Cool, I was actually thinking about putting a k&n air filter system on it anyway and eventually a better exhaust so that'* good to know! Thnx!

For what it'* worth, I won't use K&N filters. At the risk of starting an opinion battle: When they are over-oiled (and sometimes when they're not), a little bit of the oil collects crud all down the intake tract.

Not to mention findings such as these: https://nicoclub.com/archives/kn-vs-oem-filter.html

My $0.02