9.5 should be ok, but it may be able to be adjusted, depending on the regulator design. They just set a new propane tank at my house and adjusted the regulator to 10.5. It was 13 "out of the box". Better to have a lower propane pressure than a higher one.
2003 GMC 2500HD 4X4 D/A Ext. Cab
Propane Powered Honda EU2000i
Lots of Hot Sauce!
Air # 283