Hey guys I don't completely understand backspacing so I need y'all's insight. I have a 2wd 96 1500 with a leveling kit and I barely rub at full lock on my 31x10.5x15's with 15x8 rims with -19 mm offset. I am putting in a 4" spindle lift and want to throw on some 33x12.5's cause I think 33x10.5's may be to small but I'm worried if I put then on they will rub horribly! Because my 31's already do now. Any input welcome and also I saw a guy running the exact same setup I will be running except his rims wer 15x7 with 0 offset and he doesn't rub so will I? I'm so lost!!