After installing my 31" BFGs on stock 15x7 wheels,
I got some tire rubbing on the sway bar and Camburg extended radius arms.
Since I don't have money to buy new wheels with correct backspacing,
I got cheap solution.
First, I measured approx. distance from I-beam knuckle to spindle knuckle, so they won't rub on
sway bar or radius arms. Do this on both side. Note that diatance may be different.
Then I got some grade 8 bolts cut to the length that I measured.
Or u can have bolts cut a little longer and adjust them later.
When you do that, make sure they are not too long to turn the wheel =)
I also ground the surface of bolts and I-beam knuckles since they had to be welded.
Then I took bolts and my truck to local muffler shop and let them weld(paid like $10).