I have ordered 120# injectors and a 40 micron SS filter element for my post filter. Will order a GM sensor as soon as I figure out what AN fitings are needed to connect to it. I will place it in my -8 return line using a branch with two "Y's" and -6 or -8 line. I like the layout shown in the earlier photo of the Mustang with sensor in the return line. The main return flow will not, of course, go through the sensor. I think I have the wiring of the sensor into XFI fairly clear in my mind.
Time to take the leap!