Auto OD questions

Charrlie, What gears are in the truck ? I will guess 3.55. My 01 Ram 2500 had 3.55 and would not tow in OD.If you would breath on the gas pedal it would down shift out of OD.Was only good going down hill !! I ended up putting 4.10 gears in it when I was racing and towing my car.Now my 88 Ram is a 1 ton and has 4.10 gears.Hardly ever tow anymore and have been debating changing the rear gears or go OD.