Does anyone know what the widest tire will fit on a 94 kick w/ 3inch body lift and trimmed?  i'd like to go w/ an 31x11.50 super swamper LTB but i'm not sure if it'll rub.  i've got a set of 31x10.50's on now and they clear fine.

What backspacing are you running? I've got 12.50's, but my wheels have 4" of backspacing, and do a little rubbing on the frame at full lock with a bit of articulation.

i'm not real sure :-/  a friend gave them to me.  there the american racing black 15x8 i believe?  how can i find out what the backspacing is?  and thanks for the help

Depending on what tire brand your running now, they should fit. Some brands run small 31's actually 29-30 diameter, and Interco usually runs close to true measurments. If the width causes some rubbing of the lugs on the intercos, you can always adjust your steering stops a little.

Zig