Air ride suspension systems, have a specific ride height, built in, and raising it would be possible but very expensive and possibily detrimental to the handling and control of the coach. Raising the center of gravity and changing the suspension angles, a real nightmare.
Have you driven the coach and had any issues with low clearance ?
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.