So I have searched the site for hours and still aren't positive on which size tire I need. Yes I even looked at the tire fitment chart. Tires will be on 2010 z71 silverado, 18" wheels, and 2" RC leveling kit. I am getting Toyo MT and can't put my finger on the magic tire size. What I've gathered is a 285/65/R18 should fit perfect?? My friend at the tire shop says I should run a 275/70/R18. Please help me decide. I could be wrong about both sizes.