I'm surprised that no one has mentioned the solution Glenn proposed last November. As truck tires wear relatively quickly and trailer tires generally don't 'wear' out but need to be replaced due to age, why not replace your half used truck tires with new ones and put your old truck tires on the Montana. Both are usually 16" and both are similar sizes with the same load rating. You can get to Glenns topic at the following.
http://www.montanaowners.com/forums/...chTerms=+tires
Has anyone actually done this yet? I need new Montana tires this summer because mine are showing age cracks although the tread is like new!