Ram owners. What gear while towing on highway?

My father has 4.10 and I have the 3.42. He just sets it in T/H and goes 62-65. I will let my truck use 6th on the flats and downhills, but will manually downshift to 5th for hills, and sometimes force it in to 4th for big hills. I do this before it really starts pulling the hill to limit stress and heat.

In my experience the Ram transmission logic wants to hold gears way too long, even in T/H.