For someone that want's to upgrade to 17.5" tires I have 4, 17.5" rims for sale. They are used but are in very good condition. I bought them two years ago from Trailer tires and wheels. They are 8 Lug Series 03 Machined Hi Spec Aluminum Trailer Wheels with 9/16 Lug nuts, bolt in valve stems and Stainless steel center caps. You can see them at their website: http://www.trailertiresandwheels.com/17.5x6.75-8-lug-series-03-hi-spec-aluminum-wheel.
They are located in northern Illinois near DeKalb. I'm asking $600.