I pull a 10K fifth wheel with the 6.2 with a 4.30 diffy. It is just me but I would never operate mine that way. Mine wold go crazy under the hood on an incline with the cruise on. I see no reason to have the motor howling just to try to keep a couple of miles up on the speedo.
I anticipate the need to have more R's and just drop a gear via the electric toggle on the shift lever.
you have a lot of comments that appear to be echoes of a gasser has to be roaring up near the red line. No so on the way I treat my equipment. Sure it has to be up around 37-38 to produce power needed on a hard pull and I do that but not by letting it go nuts with the cruise on.
drive it the way you want to, but I would be hesitant to pay heed to advice given at random without a preface that the advisor indicates that they pull with a like set up.