[767Jockey]

I have a custom built gas tank in my car. I just found out (DUH on me...) that it is set up with a reserve type feature, having one fuel pickup closer to the floor of the tank than another, so that when the main supply runs out I can switch to the reserve pickup and use the remaining small quantity of fuel to hopefully get to a gas station. I have two setup choices. One is to use only the "reserve" pickup so that my tank can be used until dry. The other is to use the two pickups with the lower one acting as a reserve. I suppose I'll need a valve of some sort and perhaps two pumps to do that? Can anyone fill me in on how this originally worked, and maybe what type valve and would be needed and where you guys using this setup have the valve located?