Max back space on a DSE sub frame

[KPC67]

Ok so I am am trying to fit a 275/40/18 on a 10" wheel on my car with a DSE subframe. Is there anyone on here with this combo? If so my question for you is what is the most back space (center of the wheel as close to the outside of the car) I can get away with before the wheel will hit the tie rod end (looks like that will be the first thing) I do have the tire mount mate but it am not trusting it.
DSE recommends a 6 1/8" bs but I wanted to get some other opinions..