i have a 2008 1500 ltz with a 2" leveling kit in front and airbags in the rear. it came with 20" wheels and 275/55-20 tires. I wanna put 18x9 wheels and 295/65-18 tires on. im really confused on backspacing and offset. i would like to widen over stock, but not so much as there is major trimming needed. Any help would be great. Thanks .