Our shorter 23'-8" long Phoenix Cruiser model 2350
HERE is 9'-10" to the tippy top of the a/c unit. It is 3" lower than the one mentioned above by Richard because the E350 chassis sits 3" lower than the E450 chassis, and also 3" lower than the Sprinter chassis option. A new 2015 Model 2350
HERE has not changed much over the years, and surely not it's height.
All 9 models offered
HERE are no taller than the 10'-1" Rich mentioned. If you "almost" like a particular floor plan, the factory is very accommodating to make changes that won't impact mechanical stuff much, and won't gouge you to do it. BTW, most slide outs in every model are optional. With exception to the few double/queen beds in slide outs, all can be deleted for a handsome savings.
We have a 9' 11-1/4" tall opening in our garage door which offers just over an inch clearance to the a/c unit. It's tight but it fits at full tire pressure and empty. Loaded with fresh water and all the rest and I get a little more.