you can run 31x10.50's with a BB, however if you dont want to run i would get a 3 inch kit. i have the BB and OME springs which nets at around 3.5 inches of lift. i am running 31's with no problems. i highly reccomend this setup but you can get away with just a BB.
I'm running ~2" OME lift (springs, 1" packers) and just ordered the rims for my 31" Mud King XTs.
I'll let everyone know here how it turned out, seems that sometimes a 2" lift will fit 31s well, sometimes it won't.
I am in sort of teh same boat as well. I am in the process of boosting my grand. I have a 2" kit in the mail. I am planning on running 31 10.5 dunlop mud rovers. I hear alot of mixed responses when i ask people. Some say itll rub, some say it wont, some say trim the fenders, and others say get a taller lift kit. I eventually talked to the manufacturer of the BB i bought and they said measure the tires. I did. It turns out that most 31" meats are only like 30" or 30.5" tall, 32's are only 31.5, etc. So i think they will fit. I have a stock height grand right now and am running 235/75/15 which are almost the same ( other than like 1mm smaller) as 30" or as they are actually measured, 29. I figure if i add like 2-2.5 more inches, ill be clear of any rubbing. We shall see in a few months though when i save up enough to buy some new meats.
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