I have a 05 auto and recently installed Brown Dog 1'" MML without a body lift. I haven't had any problems at all other than slight vibration in gear at idle from the mount. As mentioned previously unbolt the fan shroud and transmission mount before starting.
Without a BL, you will need to relocate the fan shroud 1" higher on the radiator. This will require notching the shroud slightly around the upper radiator hose (I used a Dremel plastic cutoff wheel). Next, you have to drill new mounting holes in either the fan shroud or radiator. I chose the radiator as it appeared safe, easier, and cleaner once complete. I found the easiest way was using a self-tapping screw and
90* DeWalt drill driver attachment. After running the self-tapping screw in and out a couple of times, the stock fan shroud mount screws fit perfectly.