factory second fuel tank

[Zorm]

found a aux fuel tank in a yard here and want to know what all I should get from the Cherokee that it is in. does the aux tank gravity drain into the main tank? Should I get the fuel tank selector, like from the 70's Ford "camper special" trucks, to manualy switch the tanks and wire in a toggle switch to switch the sending units?
Thanks

[joe]

There were no "factory" aux tanks on Wags/Cheros so it's an add-on which means it could be plumbed any number of ways. Some were higher and drained into the lower stock tank. Some have a split Y type fill pipe where you turn the nozzel to fill either and some have two separate fill pipes. Some ran two pumps, some run just off the original tank/sender/gauge, some have two senders and a switch to run off the orig gauge etc etc. Basically along with the aux tank I would grab everything remotely fuel related...fill pipe(s), vent lines, switches either mechaniical or electric, wiring, senders etc.