where to mount valves??

alright, looking at the fittings that I got with the kit Im gonna have to stick my valves right to the T. so with the T the 2 valves and the 2 fittings the whole thing is like a foot long. where do you think I should mount these? also how do I mount um, dosent look like there are any mounting holes or anything. and anyone know how good blitz valves will do under the truck? like will water and shit mess um up?