you just listed about every option the ranger has availible...that is not a plain jane truck!
usually v-6 extended cabs got 8.8's...i wonder if your axle got swapped at some point (that is unless youve owned the truck since new).
i have not owned the truck since new , but the axle code on the door jamb is 86 , which , according to this site is a open 7.5 with 3.73 gears , and there were more options , it could have had the off road package and the bigger wheels , the stock tires and wheels for this truck are 235/75R15