Signed up just to put this to rest. I took the plunge and put Nitto Ridge Grapplers on today in 285/65R20. Stock Duramax Denali wheels, no lift, no level, I only removed the lower air dam/valance. Zero rubbing at lock, forward or reverse, and no crank on the T bars
2015 2500 for reference
I hope this helps someone else since I searched forever and couldn’t get a good answer.