re doing air system

I'm re doing my air system and going to be mounting the valves under the truck. Does anybody have some good locations or pictures of clean valve set ups? Would prefer under the truck but in the bed would be okay to.The truck is a 1991 Chev fullsize extended cab.

Im going to start working on redoing mine also, so pics would be cool.

any body?

bump 

Mine aren't exactly under the truck but b/n the frame and bedside on custom made aluminum manifolds.  There are no dump valves in the pic.