Yes, it is
I don't know anything about the Yellow box, from what I read it is only used to correct up to 12% deviations, so could only be used in a Ranger after signal was already corrected to 8,000ppm, so at the speedometer would be best
The SGI-5E would do it for sure, but you would take the 4WABS module out of the picture for this, by pass it, as far as speed signal is concerned
SGI-5E would be hooked to the rear axle VSS, 2 spliced wires to speed IN + and -, VSS stays hooked to ABS module
Then its 8,000ppm output(Ford) would be connected to the grey/black wires, spliced in at any point to any of those wires, BUT disconnect/cut the grey/black wire on the ABS module so you don't have double speed signals
The grey/black speed wires are already connected to each other, so you just need to splice new signal into one of them
Then its just a matter of fine tuning the pulse, up or down, to match correct speed with current tire size, if you change tires then re-adjust
Many have used this when swapping in V8s to Rangers because they loose the transmission/transfer case VSS, 1997 and earlier Rangers still used speedo gear setup
Or if they put a 1998 or newer transmission into a 1997 and older Ranger, lol