Auxiliary in bed fuel tank question

No worries fellas was just curious to see what guys have done out there. I considered gravity feed however it is illegal up here and I require yearly safeties. Plus I wanted the ability to fill quickly and push the fuel through a quality filter. I can fill my stocker in about 3 min. I believe my only option will be to tap into the existing vent line and run a hose back upto the aux tank to one of my spare ports ontop of the tank.... I was discussing with a friend and we figure the vaccume created by the pump in the aux tank will essentially in turn suck The air out that isn't being displaced in the trucks fuel tank via the stock vent tube.