Will it rub the KDSS bar, most likely. Will you be able to detect it from the driver's seat, ehhh mmmaybe?
I have that exact wheel and tire combination and I ever so slightly rub on the passenger side of the KDSS at full lock on a left turn (mud flaps removed and plastics trimmed in front part of wheel well). It rubs enough that I can feel the tire lugs through the steering wheel; I only feel this at the very end of steering wheel rotation.
Folks want a hard and fast rule on tire size and fit but unfortunately there are small differences truck to truck that make it impossible to definitely say. My wheels/tires on another truck rubbed on the driver side bar. The body/frame alignment seems to vary a couple millimeters between trucks per Rob's experience and measurements, so when you're pushing for max tire size these extremely small variations can present themselves in different locations.
In my opinion, this small rub is worth the trade off and I won't ever run less than a 285/75. Now if it was a BFG or some other brand in the same size, would it still rub? Not a clue. The only thing I would do differently is custom order my offset on the EC wheels, I actually would go slightly more aggressive and push them out a little more, much like observation in the previous post. I'd probably order something between +25mm and +30mm.