if it has an inspection cover,you can R&R/change the oil and have a looky see

its stamped on the edge of the ring gear along with the yr and part #

8 3/4 is a little bit of work to pull it just to look though

on my 3.91 it turns 3 7/8 full turns

on a 2.76 gear it will turn 2.75 turn

3.21-3.23 is 3.25 turns

3.55 is 3.5 turns

ect...

make sure your not sliping the spider gears,it will throw it off on the count