Got my Tune On!

[Marky Dissod]

For the Suburban 4.10 were better than 3.73.

If talking about a 4L60E (or even a 4L80E), I'd agree enthusiastically.
My Tahoe Z71 has 3.73, and every time I floor the go-pedal, I die a lil inside. (I am too accustomed to V8 Caprices with 3.42 or 3.73.)
Having driven a 4WD Tahoe with 4.10, I'm absolutely sure 4.10 would improve city MpG, might hurt highway MpG SLIGHTLY, and would help the 4L60E last longer enough to defer and offset the rebuild cost til she convinces me to buy a more fuel efficient dingus-car for shorter trips.

For a 6L80E, whether Tahoe or Suburban, 3.73 seems an ideal compromise between metro / urban MpG, highway MpG, 6L80E durability and longevity, and fun-to-drive ...

UNLESS you plan on towing over 7000lb with it, in which case I'd go past 3.73 to 4.10 to further protect the 6L80E.

For best results, ecm & tcm reprogramming, and if you can afford it, a torque converter upgrade ...

 

[B-train]

I had a 2000 silverado 4x4 with 5.3L and 3.73 gears. It was a fantastic setup. My dad had the identical truck. 1999 4×4 with 5.3L and 4.10 - that thing hauled A*S*S! And it got almost the same fuel economy as mine did - basically splitting hairs depending driving habits. It would pull a trailer better than mine with 3.73. I would opt for 4.10 in an LS any day.

 

[Marky Dissod]

... had a 2000 silverado 4x4, 5.3L, 3.73 ... fantastic ... dad had the identical truck. '99 4×4, 5.3L, 4.10 - that thing hauled A*S*S!
And it got almost the same fuel economy as mine did - basically splitting hairs depending driving habits.
It would pull a trailer better than mine with 3.73.
I would opt for 4.10 in an LS any day.

THIS.