So I need a little help, I've been looking at getting some new tires for my truck and was wondering if anyone can shed some light on this for me. I have an 03 silverado 2500 with a procomp 6" lift. It currently has 35x12.5 18's on it. I'm looking to put 37x13.5 18's on it but everyone I seem to call has no idea if they'll fit. Any help would be great! Thanks