I put the cpp kit on my 59 1/2 ton long bed. My truck had an aftermarket 15 inch rim with 275/60R15 tires no issues with clearance. I am also putting the Cpp kit on my 1940 gmc. The 40 is running 16 inch artillery wheels. I had to do a wee bit if grinding to make the wheels work, but they worked without a spacer.