It depends on the size of tire you're running and wheel offset, and if you want to use the DC mudflaps.
From what I've gathered 33's with the 2" are OK w/o the flaps. 35's are OK w/o flaps and some beating on the wheel well. (Know a V10 dude who just did the Rancho 2" kit with double shocks, he beat the hell out of the lower inside rear wheel well. Not noticable until you really looked, but count me out on that one!)
I'm thinking about doing this mod as well, and I think I'm going to do longer lowers. Probably from DT as their only a couple of hours from where I live.