[Sledge]

I was swapping out my transmission recently (with the help of a friend who used to own a transmission shop many years ago--how lucky can you get) and I was trying to find the serial number. I could find a cast 13-52-xx-xx number on the left side of the forward case, which we both took to be some kind of part number. We also saw a number etched into one of the flanges on the new trans, and a similar number stamped into a flange on the old trans. We think those etched or stamped numbers are the serial numbers. Anyone know otherwise?

As usual, all help appreciated.