Right now i am running exactly that, 31's 2"BB with longer shocks, and when diconnected and fully articulated i just slightly rub my fenderflares. It is not enough to do damage. Plus if you put on new bump stops you will be loosing basically all that you would have gained with the disconnects.
Did you get longer shocks with the BB? If you didn't you probibly won't even rub at all.
I would definelty recommend getting the disconnects though, i absolutly love mine.
:beer: