Here's my truck . I have 15x8.5 tt2's with 275-60-15 firestone indy 500 tires on all four corners . I have (about) 3'' / 5'' lowering kit on this truck . As you can see theres plenty of room and they have never rubbed . The offset is 4.25/4.25 i think . I ordered these out of summit racing catalog and they knew what it needed. Good Luck . Buying a set of wheels that dont fit or look bad sucks . I had a bad experence with a new set of 20'' being the wrong offset and dont want you to go through that . good luck - curt