3/8" Feed line, 5/16" return line, and 1/4" vapor recovery line from LH tank run across the crossmember at the to the RH rail. This is done via hardlines. They go into the switching valve that is mounted inside the RH rail. The RH fuel tank just feeds directly into the switching valve with rubber fuel lines. The 1/4" vapor line goes into a tee under the switching valve and passes off to a hardline in the RH rail. One set of 3/8" and 5/16" lines go down the RH rail to the engine.