Looks like mine on my '93. The tailshaft sensor is the VSS that goes to the PCM. As depicted above, that sensor shown goes to the floor shift lever.

I left everything original except for hooking up the 4wd Low wire from the PCM. That is something that needs to be done. Since the drivetrain will be spinning at a much slower RPM compared to engine speed in the 4 Low position, the 4 low wire from the PCM must be grounded so the PCM "knows" the drivetrain is in 4 low and shifts the trans accordingly. I mistakenly removed that from my modified original harness and now must repin the PCM and find how I can get the wire grounded in the 4 Low position. It will take some doing but I figured I'd mention it so someone else doesn't make the same mistake I did.