Here some info for you... Axle width: 73-78 ~ 53" 79-83 ~ 55" 84-88 ~ 57" 89-95 ~ 58.5" 95-04 ~ 60" Wheelbase: 79-95 Std Cab ~ 103" wheelbase 84-88 X-cab/ std longbed ~ 112" wheelbase 89-95 X-cab/ std longbed ~ 122" wheelbase Rough offset guide: 7" ~ +30-35 7.5" ~ +35-40 8" ~ +40-45 8.5" +45 and up.