filler neck

[cameyer]

I know this has been covered a million times but i cant seem to find the info i am looking for. So here is the issue, i have instaled and under bed gas tank kit from lmc and have it mounted up, but can not figure out how to create a filler neck. i do not want to have the fill come up through the bed because i will be frequently hauling things in the back of my truck and dont want to risk the filler being blocked when it comes time to fill up. So i would like to have the filler neck be on the side of the bed. Could any one give me any advice on how to do this? I am totally stumped.