With the 4" backspacing its only changing it 2" (from 6" to 4") and it should still work just fine but your wheels will poke out a touch further (which may look better depending on what style you like). Myself i got those with 33's (admittedly with a lift) and they fit just fine. I've even seen other people run them as well they were still able to turn lock to lock with no problems.

 

yeah i want them 2 stick like 1 inch