Rockstars are 18x9 with 0 offset. That means the backspacing is 5" and the wheel is 1.5" wider than stock. You will likely get some rubbing on the fender where the mudflap used to be. It will only happen when turning and compressing and may only happen after your lift has settled.
I am running 275/65/18 Toyo ATs and have 18x9 with 0 offset wheels and rub occasionally.
Is your lift a spacer type or adjustable coilover?
If you want to run this setup, consider a mild body lift as well, say 1/2 to 1". That will fix the rubbing while compressing issue. 4Crawler makes excellent complete kits. They are not difficult to install, but count on a full day in the garage to get it done.