You can get 35s to work really well on the D30 with just some chromoly shafts and beefy u-joints. If you want to go the extra mile, it's up to you. Plenty of people thrash them with just the upgrades I mentioned and are fine. Myself included. Lots of rocks in JV and the occasional trip to some mud. Not a lot of high speed stuff though.
4.0L 5spd, D30/D44, AlloyUSA, OX, TenFactory, ARB, Atlas, Currie, Savvy, 35" Kevlars