I got a four door with 30s. when wheeling a few weeks ago on the applegate lassen trail, so just rough road and lots of mud. Came home and it was leaking gear oil from front diff. anyways so i had to tear it apart and had a set of 5.63 on the bench so two birds with one stone. I had broken a bolt on my diff and another was totally stripped. I have drop diff brackets so probably more leverage on it.
I going to 31s next, but I will have a steel diff, but i think thats the limiit.