Depends on a bunch of factors to determine if 4.10s are going to be a good fit for you or not.

 

Unless you do nothing but highway, I'd absolutely go 4.10.

There are no downsides in my opinion. Even the mpg difference on the highway is negligible in my experience.

On the older 4 speed trucks, you can't beat 4.10s for stock size tires.

 

Unless you do nothing but highway

Well hunting and fishing and pulling a 16ft jon boat. Lot of dirt roads on our game lands. Stock tires.

 

I'd definitely go 4.10.

A good locker is also not a bad upgrade. There are several good ones, you'll just want to look at the operation and characteristics of them and decide which suits you best.

 

373s are a nice compromise. That's my preferred ratio. Good opportunity to add a nice locker.

 

Ok been waiting on this guy said he was going to swap it out for me either Mon-Tuesday. Well he never did so tomorrow I'm taking it to the shop on dolly. Thinking about this setup going with 3.73 gears limited slip plus whole rebuild.

 

If it was my truck, I'd go with 4.10 with a posi carrier. Going from 3.42 to 3.73 just isn't much of a change. If your truck is 4x4, just remember you'll have to do both diffs. You'll also need a tuner to correct your speedometer.

 

Although newer than yours I went from 3.42s to 4.11s on my 09 with the 6 speed. I would never want a taller gear than that in any truck ever again. Love the difference.

 

Honest question.
What's wrong with 3.42's?
:?:

 

They suck on the 4 speed trucks, and are marginal on the 6 speed trucks.

Add bigger tires and they really blow.

 

^ yep

I had 3.42s on mine and pulling 5k trailer it would gear hunt on the highway. 70mph and OD on and it would still drop to 4th at the slightest incline.

Had I left it all stock and kept the TINY 245/70r17s on it they would have been ok pulling that probably but it looked goofy for sure.

 

It's just a 2 wheel if 3.73 isn't going to make much change that will be ok with me. Nothing wrong with 3.42 it's been in for 348,000 miles so no complaints. I just want some options for better traction, hauling my boat, boat ramps, etc

 

UPDATE!!!!

So the rear end got rebuilt all new components except for axles. Shop said they could be reused. $1800 later been driving it going on 3 weeks everything seems fine. 1 year warranty 90 parts and labor. Guess he wasn't listening about the gear change so it was replaced with 3.42 gears. No problem just glad to get it back.

 

I am swapping my 3.42 gears for 4.10 with a new locker as well. Has anyone upgraded your gears and had ABS censor show up on the dash?
I have a 2015 Silverado 1500

 

Glad you got it back going OP, a little on the high side but sure is better than a new truck.

Les did you tune the truck so that it knows you swapped gear ratios? when I did my 09 I had zero lights come up.

 

I just scheduled the gear swap. However I did the Diablo i3 tuner to change my tire size when I got my truck lifted

 

Just use the diablo to change the gear ratio to match what you put in and it should be good to go.

 

Honest question.
What's wrong with 3.42's?
:?:

They're sluggish and eh. If you do towing, 3.73s or 4.10s are definitely the way to go.

 

They suck on the 4 speed trucks, and are marginal on the 6 speed trucks.

Add bigger tires and they really blow.

That's a pretty broad statement because not everybody has to have their truck screaming rpm's while driving on the highway or heavy towing with 35's.
For me with the 4 speed 4.8 rcsb, it's fine and gas mileage is pretty darn good and the truck accelerates nicely.
It handles a full bed fine and I have absolutely no gear hunting.
I think 3.42's are just fine for some.
My 2 cents.

 

Now compare that same truck, but with 4.10 and the truck with 4.10 will do everything better. Only potential downside is you may lose a little fuel milage on the highway. But even that can be a wash sometimes.

In my opinion, the only way 3.42 gears can be bearable is if you never tow anything, don't care much about off the like feel, and never go bigger than stock tires. Maybe in a lighter weight 2wd truck, 3.42 would be OK, but after driving both, I'd never opt for the 3.42 truck under any circumstances. There is just no downsides to me of having the 4.10 gears, especially on the 4 speed trucks. The 6 speed changes things a little, but my opinion is still the same, in that all these trucks should have 4.10s in them, or at least have it as an option again.

But yes, if you never tow, keep the truck stock, and just put around, the taller gears are ok for some. If using the truck like a truck, especially towing, and like to get a little meatier tires under it, the tall gears just don't work the best. These motors aren't stellar as far as power down low, so they definitely benefit from running a little higher in the rpm range, and having more use of the rpm range throughout the gears.

 

They suck on the 4 speed trucks, and are marginal on the 6 speed trucks.

Add bigger tires and they really blow.

That's a pretty broad statement because not everybody has to have their truck screaming rpm's while driving on the highway or heavy towing with 35's.
For me with the 4 speed 4.8 rcsb, it's fine and gas mileage is pretty darn good and the truck accelerates nicely.
It handles a full bed fine and I have absolutely no gear hunting.
I think 3.42's are just fine for some.
My 2 cents.

You asked a question and he answered.