the back spacing on the rears is 6.900" which isn't ideal, I use long wheel studs and 3/4" spacers to get them centered just right. Depending on what brand wheels you are looking to get, some companies will send you a rim and wheel center that is unwelded so you can fit them perfect, then send the company the specs and they will weld them up for you. Here is a picture of the same wheel/backspacing with a 275/40R17. I didn't like the fact that it didn't fill the wheel well as much as the 305 here are a couple of shots for comparison.
1st: 305/45R17
2nd: 275/40R17
3rd: 275/60R15