HOw you can find the gear ratio:

there are two ways I can think of

1.Research and asking

two actually counting

If you look at www.vfaq.com there is a page on the gear ratios.

What you need to do is actually turn the inputshaft for example and count how many times the output shafts turn.
For example you trun the input shaft 50 times and your fron axle outputs turn 20 times. The tcase shaft turns 30 times. And then you find the gear ratio for your car's rear end and find the number that the rear wheel WOULD turn. THEY MUST match.

If the tranny is on the car it gets a but harder but with more accurate measurements involving angles you can do it.

Anotherway that I would do it is to put a 22 spline Tcase on
LIFT THE CAR
let it run with for wheels off the ground and see if they are turning at the SAME rate. In fact I think this is the best way considering installing a T case only takes 15 minutes.

Amin