Any issues with mounting the Andair fuel valve directly to the tunnel cover. Will it create any flow issues when the tanks are down to the last five or ten gallons. This brain bubble popped up when I thought about the bracket location inside the tunnel for the Van's stock valve. Also, because the fuel raises to the valve, drops to the filter and pump, then back up to the firewall, a low point in this section of the fuel line. Should a fuel drain be installed at this low point.