Anyone changed their rear end for more towing capacity?

I don't think you will notice nearly enough difference in towing ability by switching to a 3.42. As others have said- 3.73 or don't bother with it.

I had a 1/2 ton with the 3.73 and towed about the same weight you report- While it slowed some on the hills, it did get the job done and that thing had a lot of towing miles on it!