I thought I'd update my progress so far on this thread.
The Motorcraft SW873B sending unit won't fit. There is a steel line running to the bottom of the power steering pump, and the sending unit hits it, and I can't get the threads to line up well enough to start them.
I found another sending unit, Motorcraft SW2433 and have ordered it. It is smaller than a SW873B, the only problem is that nobody stocks it, I should have it tomorrow.
Use the bottom plugged port and Get a 90 degree elbow in brass so the sending unit points back. Should fit then. Just leave the original in place or replace it with the plug removed from the bottom.