I just got back from a camping trip and towed my 5er (10k lbs) over to the coast, only a few hills on this trip and a couple of steep short hills but what I noticed is if you are going to run 22.5" wheels or any tire approx 36" tall and you have 3.73 gears, i think it would be best to do itwith a 6 speed truck and not an automatic or a 5 speed like mine, I have no intentions of removing the 22.5" wheels instead I choose to just add more power (Bigger Turbo,injectors & Fass ) I noticed if I didn't rev it high enough before I shifted the rpm would drop down to 1200 to 1500rpm although I now tow at 65mph in 4th gear instead of 5th and i do like that part=cooler EGTs and right in the power range of 4th gear, my MPG while towing is down about 1.5 to 2 mpg when Towing although when not towing i am up 4 mpg. With my somewhat agressive driving habits I would average between 14.5 and sometimes 16 mpg with stock tires and wheels, so far now with the new 22.5" tire set up,I have averaged 20.7 mpg on a 80% freeway trip,and 18.8mpg on a normal around town and some freeway tank of fuel and yes these are hand calc numbers. I am now at 1500rpm @ 55mph and 1750rpm @ 65mph in 5th gear
So in conclusion I dont tow every weekend etc and I actually have to use my 1st gear now when taking off but the gearing difference is not enough to bother me, so if anyone is thinking of doing this or something similar I would recommend 4.10 gears and a 6 speed to reduce any gearing loss
These wheels do look awsome

 

Tripper , I luv the looks , there is a white dually with same wheels here in West Sacto that I see now and then.... good looking with the low profiler on it.

 

White Eh? Mine is white and I am around West Sac sometimes...

 

LOL , well it seems I see this truck most of the time at Jefferson and Merkeley or West Capitol. if it is you , that is one sweet looking truck.