If you where running a non cv shaft in the rear before the duals I'm about %100 sure your going to have to rotate your pinion up. You want you pinion 2* under the slope of the shaft with a cv, forget about the tcase flange.
For the front I'm going to say you would want a standard u joint shaft (non cv). I'm basing that guess on the height of your rig and the fact your running duals. I could be wrong though. Good luck