Most of them are 5'8", event buses are taller due to basketball players and huge footballers. I'm 6'4" and, for me, they all need a roof raise. Be careful, Crowns do not have slab sides, they bend in at the lower windows and should be extended/raised at that level, saves on problems. Gillig Buses are slab sided and the three axle long buses have the same engine/layout as Crown Buses, (Engine under the floor!). Also, because the engine is underfloor, you have to build to allow for access to the motor. As a result, it is important to completely remove the floor in order to inspect the under floor super structure to repair anything that looks questionable!
