i just did the ome hd lift and bilsteins, the ride is way better than stock. my wife hated driving or even riding passenger in my kj before, today we went to a truck show and i felt we had to take it, she was surprised with the change, said it felt liek a new car. for being the hd springs, it isnt firm at all, i think id be pissed if i bought anything less. im running the 245 70 16s which are 29.5, it sure looks like there is room for more, but i cant say if a 31 would fit without the top plate or clevis lift, but those are cheap and easy if needed. i dont wan tot buy new rims, but im thinking of doing the 1" wheel spacers.