Has this 915 been regeared?

Here are the approximate road speeds and corresponding RPMs. This is on 225/50 tires.

1st gear: 3800 rpm = 30 mph

2nd gear: 2200 = 30 mph

3rd gear: 2500 = 50 mph

4th gear: 2000 = 50 mph

5th gear: 1800 = 60 mph
2100 = 70 mph

what year 915?

Doesn't seem like its stock based on all of my gear charts . . . if you know the year or its final drive is 7:31 or 8:31 you could figure out the gears.