I want to get some new rims and tires for my truck, I also plan on lowering it about 1"

I was just wondering if anyone knows the backspacing on this truck....I have no idea what wheel size is the biggest/widest I could fit on the truck.

I'm probably going to get 18x7 or 18x8

any help would be..... helpfull

Thanks

well i have 15x8 corvette rally rims on my truck and they dont rub or anything, so i kno that 8" works fine. you should be able to get 18x8 to work just fine