I have a 1986 International S1600 with 9x20's right now. I just picked up a set of 8.25"x22.5 rims and will be mounting 11Rx22.5's. My question is, will I need different size spacers for the rear duals? If so, what size and where can I get some. I am also looking for a good source for tires in the San Diego area.