2001 F350 7.3 Dually Guages and Gears?

[H. John Kohl]

You are asking good questions.
I personally like the trans temp gauge you know when it is getting too hot.
The rule of thumb is to go down hill at the same speed and in the same gear you pull the hill. Since you have automatic it will down shift when it needs too going up.
I think you are going to have to set the throttle position by feel depending on the grade of the hill.
Best of luck and safe towing.