Put your truck in entry/exit mod and then measure to the tip of your antenna.
I've got 6'5'' on mine to the FM and 6'3'' to the Sat....so I would have no issue driving into a 6'5'' or better.
I would also be willing to chance a 6'4'' depending on how hard my antenna hits when I go under the height check and how steep the ramp breakovers are
You gotta be careful of the height of those parking height limit things where the ramp starts to rise. You may be clear when on the flat part of just starting the incline but the roof raises as you climb and it may hit that height restriction bar.