dana 30 is plenty strong, dana 35 is good until you lock them, ive got a friend on 36 tsl super swampers on a 35/30 combo and he does fine, open 35, locked 30. he rock crawls with his XJ. stock axles. you cant be hard on the skinny pedal with those tires and a rear 35 but if you know how to drive you will be fine. either that or truss the 35 and get chromolies.
also have a friend with a 35 and 34 tsl's and the 35 is welded and has been for over a year. strictly dirt and mud vehicle only though. terrain means alot

 

what about taking the trac lok out of the rearend is that hard?

 

Taking the Trac-loc out is not hard at all just like any other diff. If you have a trac-loc you will need a new carrier to be able to install a locker though.

 

this is my first time working with gears. whats a carrier?