With a 4,44 ratio you would reach 137mph at 7000rpm..
With a 5,5(!) ratio you would reach 111mph at 7000rpm..

Both results with the same tyres, box etc. as above..

Often there is a little sign mounted by one of the bolts on the casing..
But its easy to remove the casing, and the ratio should be printed on the crownwheel(?).
It's like that on org. diffs.. Think it's the same on other diffs aswell.