My son bought a 2015 GMC Sierra 1500 short bed single cab 4wd and wanted to put more aggressive tires on it. He ordered tires and rims online already mounted and balanced 33X12.5X18 with -24MM offset rims. Of course they don't fit his stock Sierra. How much lift will he need to allow the tirse full turning radius without rubbing? He is wanting to just do a 2" leveling kit. I think he may need more than that. Any help will be greatly appreciated.