Anyone changed their rear end for more towing capacity?

There is nothing wrong with running a truck with a six speed in 3,4,or 5th gear. If you look at the spreadsheet in a previous post and add these numbers for a 4.11 gear you will find changing a 3.08 with a 4.11 is almost the same as running one gear down above second gear with the 3.08.
1st. 16.56
2nd. 9.70
3rd. 6.29
4th. 4.73
5th. 3.49
6th. 2.75

After first gear there would be nothing to be gained by changing to a 4.11 rear end if you use what a transmission was intended to be used for.