The height is speced with the trailer leveled out on a level surface. Unfortunately, your towing height will be different because of your truck, it's suspension options, drive configuration, tire height, etc. My truck is 4WD and has the HD suspension, it's easily 4-6" taller than a 2WD 2500 with the standard suspension. I've got the hitch height set where it's close to level, but it's still not where the factory measured it.
Now, they can't put one on the road taller than 13'6", so far as I know. That's the max legal height without special permits. I like the idea of setting a 2X4 across the front AC unit and measuring, I may do that this weekend.
Now-2014 Sierra 346RETS 5er BUB
Then-2002 Keystone Springdale 286RLDS TT
Nights camped in 2014-28, 2015-127, 2016-10