I agree that over-all height as specified, includes the air conditioner.
Our garage door is officially 10 foot tall but the finished opening is 9'-11-1/4". Picking a motor home to fit was a serious matter. After a year of research, we found
OUR PHOENIX CRUISER MODEL 2350 that clears by just over one inch when the tires are full and the rig is empty, including water, waste, and fuel tank.
We did not have to resort to this with our rig being on an E350 chassis, but if you have a short rig on an E450 chassis with piles of extra load capacity, you can "play" with your suspension a bit to lower the over-all height by removing a leaf spring or two.