Man there's a lot of expensive plumbing down there with dual tanks on TBI. Not only does the switch have to change the fuel feed from one tank to the other, but it also has to change the return line from one tank to the other.
There's a lot of stuff to remove including fuel lines, switches, valves etc... try and get this stuff off un-damaged as lots of guys would like to have it.
Other then that work you just need one feed and one return for the new fuel cell. Best choice for a cell would be with the pump in tank. Now your down to one.