WickedSS, you may also want to contact Marty (Syborg TT on this forum) to see if you can rent the tool below. This tool actually holds the tire you want to use. It gives you the offset of the wheel based on the position of the tire in your fenderwell. A while back he said he would rent it to me, but I am still a ways away from needing to figure out width and backspacing for my car.
