[Cal Metal]

Aussie Mike:

Here might be a short cut. If this is a '69 to '74 tranny, look at the serial number which begins with P (for Muncie). It should look something like: P3D10B.
The last letter is the operative one. If it is A, you have a wide ratio; if is is B it is a close ratio; if it is C you have hit the mother lode because it is a M-22 Rockcrusher. If this is not a '69 to '74 tranny, you will need to get all the data off of it to determine the ratio. Only these years had a desigator using letters.