According to what I can find, your transfer case is a BW 1354 with a 2.48:1 reduction in low range.
Your M5OD-R1 transmission has a 3.72:1 reduction in first gear and you've already noted your axles are packed with 3.73's.
...now all we need to do is multiply....
3.72 x 3.73 = 13.8756:1
….that would be total gear reduction, high range...
13.8756 x 2.48 = 34.411488:1
...that would be total gear reduction, low range...
If you want to know what this translates to in MPH, you need post your engine's low idle RPM and I need to know the height of your tires.
Dean