Both are EEC, the question is WHICH EEC....
up to 94 Rangers were EEC-4
95-up are EEC-5
(the numbers are usually expressed as roman numreals , "IV" for 4, "V" for 5)
OBD-2 was "On Board Diagnostics", the two represents the second
attempt of the government to force standardization, and while more
successfull than their first attmpt was still something of a failure in
"standardization".
For what you are doing you essentially need the entire underhood
harness and the compute, and yes, you need a Y-pipe as well.
Good luck finding a manual 4.0 computer for a 1995, they are
kinda hard to track down (I have one "loose" but only because
someone wanted it then changed their mind after I got it)
AD