I am putting on 17" wheels with tire size 245/45/17, this is 3" less than my stock 235/75/15's. i have never took down my spare tire, but i assume that it is the same size as the stocks. Being that it is 3" taller, if I ever had to change a tire the truck would be drastically unevev, My point and question is I dont know what is holding the spare tire in place, and was wondering if I bought another 17" wheel could I put it in place of the spare??