+1

If you're running stockish size tires and you do a lot of drag racing, go with 4.10's, if you do a lot of highway trips and are looking for a happy median between performance and economy, get the 3.73's. I like my 3.73's when I'm driving a couple hundred miles from my place in New Jersey to my friend's house in Mass, but when I'm leaving from a stop light, or launching at one of my "local" tracks, I wish I had 4.10's.

 

My old 6.0L had 3.73's in it they were nice for in city and cruising town the highway the only thing i noticed was there was no power till about 40mph

 

So i bought my 07 with the 5.3l straight off the show room floor with tow package that came with 373's. That rear end in the new trucks is also a lsd rear end. Honestly with the right power addition's that you can do to these GM engines you are better off strategizing like everybody else has said about what you really want your truck to do. Keep the lower gear size to maintain MPG, REALLY!!! Or go all out and what I like to say PIN IT TO WIN IT and who really gives a F about MPG! Just make sure you go all out and link it and everything else if your going that route. It puts a lot of abuse on all that stuff back there!

 

let the bowtie scream 4.56s!!!!! which i have and also circled rebuilt tb converter which stalls and flashes around 3000 and i get 18 mpg with no problem about 250 miles for half a tank which i got around the same mpg stock so why not have the torque on take on launch and highway power its around 2400 at 70mph on 20s believe me u would love it

 

and hey john what size and type of converter do u have to get 8mpg lol

 

so what is a good brand? I will probably just go with the 4.10s

 

AAM, which I believe is OEM equipment

 

Motive & Yukon are good brands for gears.