hey i dont kno mych about the valves i thnk 3/4 i jus kno i hooked it all up lol jus took em with me 2 get fittings n hose and i have the fronts are up down side side and the back is just up down. call me and we can talk more i think tha compressor is a 480? had them a lil while forgot what everything is there like all brand new tho.