i have 18x10 deep dish bullits on the rear and wanted to get tires with a taller sidewall and maybe a slight more width in the tire itself i currently have 275/40-18 can someone help me understand how to determine what i need change. and i have 17x9 on the front with a 255/50-17 and i wanted to know how to have a thicker or taller sidewall. i cant seem to figure this out so sorry if this sounds stupid.