HRD my 92 dakota has 8.25 with 3.55. Don't know what axle is under yours. That 2002 RT though will have 9.25 rear though and likely 3.92 gears.
If it were me I would start out by running a taller tire to see where you like the rpms then possibly do a gear swap later. Lots easier to swap a couple used tires on than make a mistake on the gear choice.
I ran a 31/10.5/15 tire on my 92 dak 2wd fit fine in the rear, slight scrub at full lock on front. The tall tire made it great as an interstate cruiser.
I have run much taller tires with a much larger truck and the same engine and was fine with the results, now I want to gear to get the same or very slightly more RPM reduction than the taller tires gave. A taller tire is less effective than a gear swap as it puts the truck higher up in the wind and most any tires are gonna be wider as they get taller witch will also reduce the effect I am after. I have thought this thru and experimented and am convinced it is the right thing for me to do, my only question now is how to do it not "if" I should do it. As for the R/T diff... yes it is a 3.92, they all were, I am just planning to use the limited slip carrier if it will fit and not the gears themselves.
