That sounds perfect!!! Go under "Search" and type in "LUBR" and you will see lots on this! I am going in that direction right now, only taking a lil longer than some. I have a 3.5" SL and 2" BL with 33x10.50x15 on 15x6 stock wheels. My fenders are cut but I plan to change that later this summer.
A 3.5" SL alone should allow 31s easily and 32s should snug inside too. I could prolly get away with 34s but I got a better deal on 33s. I'd like to go from 2" BL to a 1" BL. I should still have plenty of room for the 33s.
Skiddy gave you the best thread any uncut bronco enthuthiast will appreciate. Those guys usually say what size lift and tires they have in their signature. Happy reading! Here are a few of my favs!