Tank sending units

[akart]

I am gathering parts to replace my entire fuel system tanks,tank sensors.switching valve and dash switch. I have an '86 body and a '74 frame. the switching valve is a 6 port so I bought one of those ACDelco U7001 and 1 tank sensing unit ACDelco FLS 1001 from Summit which is the only AC one they list. Question: I see on Amazon there is a FLS 1002 which they say is for an auxilery tank. What's w/that? Would the FLS 1001 work on either tank? Also am getting the ACDelco D7089C switch which is recommended and it supposed to plug right in the existing wiring. The truck now is on the passenger side default tank,gauge works. Me thinks I have shorted a green wire to the manifold and maybe smoked the switching valve. I did replace the dash switch with another like one which has the Depress Fully printed on the bottom,no change.I just changed heads and cam and can do stuff like that but I find this fuel electrical a little complicated for me.
A little feed back please,Thank you.