2.5" lift
I have the WH 2.5" lift on my LUBR and it has room for 30's (probably 31"s) in the back, and it sits nice and level from what I can tell. I have no top on at all...I used to have an add-a-leaf kit in the back years ago, so I remember what it looked like with the back end higher than the front, and this is not the case. I really like the look of the lift, and the ride. One of my best purchases for the Bronco in recent memory...
If you do go with the 2.5" kit, make sure to purchase a set of 4 degree shims as well. I thought that they would be part of the entire kit, but they were not.
Hope this helps.
R