diff ratio canculation in car???

[chunkys mk1]

is it possible to canculate what diff is in my escort without taking it out

[baz105e]

yes, mark the diff flange with a white mark and also mark one wheel with a white mark. jack the wheel with the mark on off of the floor and leave the other on the floor. turn the wheel through one full rotation and count how many turns you get on the drive flange, this should give you a rough idea what diff you have. there is no point in trying to figure it out off of the car identification as there are no garuntees that its the origonal