You should be fine. That's pretty close to stock backspacing really and Candice (the daughter) was using stock 15x7's on her truck. It toughens up the look considerably without pushing the tires out so far they're a problem.
You will lose some get up and go, though. Didn't hurt or help the mileage from what I could tell.
Another one of my son-in-law's has been driving the truck lately and he's beat the snot out of it and it's still chugging along.