Well, your R10 is 2WD and 5 lug and then you are going to swap in a 6 lug rear axle that will require new wheels or adapters. Then you have fabrication for mounting to the springs, shocks, setting the pinion angle and adapting the brakes. You'll need speedometer calibration and you want to do this why? The axle you want to swap in is weak so you could save a lot of time and aggravation by replacing the carrier and installing a new ring and pinion.