Newer Chevy 2500HD rear diff ratios and engine differences?

We bought a 2015 GM HD - 6.0L w/4:10 ... Moved up from a 2003 w/6.0 and 3:73. Was very happy with the 2003 gearing, and disappointed that 3:73 was unavailable for the 2015 ... BUT, have changed my mind - the 6.0L/6 speed/ with 4:10 is an excellent setup. Now, if I had it to do again, I'd forget the 3:73 even if available.

We get 16+ mpg empty and between 11-12 mpg hauling a 3500 lb truck camper - and sometimes a 2900 lb cargo trailer at the same time. Very sweet match up ...