Do you know what gearbox you have fitted? their will be a marking somewhere on the gearbox casing saying something like, F-10, F-13 or F-15
Once you find this out, you should be able to find out what ratios are being used
I can never remember which way round, but the F-13 and F-15 boxes are interchangeable, one of these is close ratio, and the other is longer. I think the F-15 is the close ratio box, also not easy to get hold of