The ratio doesn't imply anything about what type of LSD it is. People mix and match all the time.

Other aspects affect rpm in 5th. Tire size is one, and 5th gear ratio is the other. The NA boxes had .838 5th gear ratios, but were externally identical. The DET boxes were .759 5th.

If you want to know your ratio without opening the pumpkin, then just crawl under the car with the rear wheels off the ground. Mark the position of one of the output shafts and the input shaft. Now count how many rotations on the input shaft it takes to rotate the output shaft once. It will be easy to see the difference in 3.92, 4.08, and 4.36 rotations. Make sure both output shafts spin in unison, by the way.