I used a thin layer of foam on the bottom of the tank and then used a piece on top that keeps the tank from being able to shift upward in the fuse. I used the block that came with the plane to hold the tank in place and glued it with thin CA so that I could remove it if I ever needed to. I use the Du-Bro brand ez fuel valves and have had very good luck with them. They also simplify plumbing quite a bit ahead of the firewall.