The PVC Valve in only in one place, and only takes one, from the POD under the intake manifold you have a kind of "S" shaped hose , from ther you put the PVC Valve into, see photo, the other end (smaller hose) goes to the spacer between the carb and intake , some also had a brass valve in line that at very high temps it would open and speed up the engine some to help cool it down, no other line should be hooked to it at all, none ,