Transit bus with roof raise to ~11 foot internal?
I'm interested in getting a low-floor transit bus like a Gillig Phantom, preferably towards the 30-foot length. I really like that having a lower floor allows me to have a taller roof raise while staying under that magic 13'6".
As per the title, I'm hoping to roof raise the bus to have an internal height around 11', which I know is rather high, but I'm trying to have a sleeping loft with comfortable headroom. The design I'm thinking of is flexible if it needs to be, in terms of height, but I definitely would prefer to get as close to an 11' ceiling (or higher) as I can.
After poking around here and the web a few times, I haven't found anyone raising the roof on transit buses. Is this because it's harder, less safe, or because of some other complication? Or are transit buses just less popular and less documented?
I'm also not opposed to having some sort of "camper top" that can be raised while I'm parked and lowered while I'm driving, if that's more practical.
Bonus question: If my bus has a governor, is it possible to have it removed?