Opinions: 3.73 or 4.10 gears?

[MichaelSE]

Unfortunately my LTZ has the uncommon-for-LTZ 3.42 gears. I want better acceleration. It will be a while before I'm able to upgrade gears (need to save money first), but I'm looking for opinions on which way I should go - 3.73 or 4.10?

Right now I can turn 1500rpm cruising at 65mph (on 285/45/22- 32" tires), so that's nice, but I'd give up some of the low rpm in exchange for quickness. I don't plan to go any larger than 33" tires; maybe 34-ish" on a 4" lift if I decide to go that way, but that's doubtful.

Any ideas? Thanks!

 

[swathdiver]

Unfortunately my LTZ has the uncommon-for-LTZ 3.42 gears. I want better acceleration. It will be a while before I'm able to upgrade gears (need to save money first), but I'm looking for opinions on which way I should go - 3.73 or 4.10?

Right now I can turn 1500rpm cruising at 65mph (on 285/45/22- 32" tires), so that's nice, but I'd give up some of the low rpm in exchange for quickness. I don't plan to go any larger than 33" tires; maybe 34-ish" on a 4" lift if I decide to go that way, but that's doubtful.

Any ideas? Thanks!

3.42s on an 2010 NNBS 2500?

 

[Bill 1960]

Six speed trans? If so you won’t see much improvement.

 

[Foggy]

I have thought of doing the same to my 14 denali with 3.42's...
Mostly because my sweet spot speed for towing puts me revving in 4th gear OR
bogging in 5th gear..
But, it's really expensive to change both front and rear diffs..
So I'll probably just add more power (again) to make up

 

[gooffeyguy]

I have thought of doing the same to my 14 denali with 3.42's...
Mostly because my sweet spot speed for towing puts me revving in 4th gear OR
bogging in 5th gear..
But, it's really expensive to change both front and rear diffs..
So I'll probably just add more power (again) to make up

Or switch to a slightly shorter tire

 

[Foggy]

I have the 20" wheels with the stock 275/55/20
I'm kinda afraid of going with the 50 series tire as there is a big drop
in weight carrying ability. My hitch weight is about 750 ish and total trailer
weight is around 9000 lbs

 

[gooffeyguy]

I'm just saying. Tire height will effect axle ratio and rpms

 

[swathdiver]

I have thought of doing the same to my 14 denali with 3.42's...
Mostly because my sweet spot speed for towing puts me revving in 4th gear OR
bogging in 5th gear..
But, it's really expensive to change both front and rear diffs..
So I'll probably just add more power (again) to make up

It doesn't have to cost a fortune... what is a fortune?

Thinking of doing this in house instead of farming it out for both of our trucks. @Matthew Jeschke has been my inspiration for such!

 

[Dantheman1540]

4.10s. The swap from 3.42-3.73 won’t be much but up to 4.10 will be good.

 

[MichaelSE]

3.42s on an 2010 NNBS 2500?

Ha, back from the dead! When I wrote this in 2016 I had a 2009 1500 w/ 3.42s. I've since traded it for a 2010 2500 with 3.73s.

Thanks all for the replies. I'm happy with the 3.73s on my 2500 at the moment.

 

[swathdiver]

Ha, back from the dead! When I wrote this in 2016 I had a 2009 1500 w/ 3.42s. I've since traded it for a 2010 2500 with 3.73s.

Thanks all for the replies. I'm happy with the 3.73s on my 2500 at the moment.

That's what I thought! How's the 2500 doing?

 

[MichaelSE]

That's what I thought! How's the 2500 doing?

Still runs great with 160k miles! It spends most of its time in the garage these days thanks to gas prices though. I have some maintenance that I've been putting off, need to drain/fill the transmission fluid and change the filter, and change all ball joints/tie rod ends. Someday I'll get around to it.

 

[992dr]

Ha, back from the dead! When I wrote this in 2016 I had a 2009 1500 w/ 3.42s. I've since traded it for a 2010 2500 with 3.73s.

Thanks all for the replies. I'm happy with the 3.73s on my 2500 at the moment.

How do you like the 2500 compared to the 1500?
I've been looking for an HD and passed on one before the situation started, now I regret it.

 

[MichaelSE]

How do you like the 2500 compared to the 1500?
I've been looking for an HD and passed on one before the situation started, now I regret it.

I wouldn't have it any other way. I'm glad I bought when I did because now the market for 2500 Suburbans is insane, especially for GMT900s. I bought mine for $16500 (2010 w/ 126k miles bought in 2018) and now, I'd probably be able to sell it for more than I bought it for, nearly 4 years and 35k miles later. If you find a good deal on a 2500, jump on it because if you're not quick, someone else will beat you to it.

The ride is pretty rough as to be expected. I put on Bilstein 5100s and it made it a little more manageable. The brakes are surprisingly strong, even when towing. The steering is definitely more sloppy, but that could also be my old tie rod ends/pitman arm. The gas mileage sucks, I averaged about 15-16 from El Paso to Tucson. All the little annoyances are worth it for the torque and power of the 6.0. My buddy has a GMT900 Sierra 1500 with the 5.3 and we've pulled trailers over the same mountain pass while I was helping him move. My 6.0 never felt starved for power like his 5.3 despite pulling a slightly more loaded trailer and having a curb weight something like 1000-1500 lbs heavier than his Sierra.