Talk to the boys at Desert Rat in Mesa. Eric and his crew do some good work. They are one of the only Desert Rat shops that do though.
What direction are you headed with the truck? What size tires, what type of offroading, what transmission, etc.
Honestly I wouldn't pay the money for a jump from 3.73 to 4.10. I would spend the money on a doubler setup or something and get the gears in the tcase for offroading instead of spending alot of money on the axles for very little gearing gain. The money spent for the gearing gain is much better for a doubler setup. When all is said and done with axle gears you could be up in the neighborhood of $800-1000 for front and rear gears. A doubler setup can be done for not much more and the gearing gain is much more.
Harley