Right now I have an M1009 with a six inch lift running 35's. My goal was to run 37" Hummer tires on the larger dana 60 and 14 bolt axle. I have read what I have been able to find about swapping axles and the problems with it. From what I have read I think if I was to switch to the bigger 14 bolts and dana 60 i would have to move the perches, but I have also read that i might need a bigger brake cylinder/bigger u-joints on the drive shaft and bigger u bolts as well. Im going to college this August and its about a two hour drive from home would the bigger axle's with the bigger tires ruin the gas milage even more then the 35's and how much slower would I be with the bigger gears? In all how much would swapping the axles approximately cost? I guess what I am trying to ask is should I get the larger tires and if so what problems would i run into?