GEM control stuff is here: What does the GEM module control? - Ford Explorer and Ranger Forums "Serious Explorations"®
The 1995 Ranger was the first year of the new EEC-V computer and GEM, it is OBD II BUT(big but) not all OBD II readers will work/talk with it, 1996 and up aren't a problem.
1995 was also the first year of electronic speedometer/odometer in Rangers.
And the 3.0l engine lost its distributor in '95, which was replaced by cam position sensor on the synchronizer housing, the synchronizer had bushings that would wear out around 80-100k miles, so heads up if you hear a squealing sound, this also runs oil pump so not a good part to fail.