Fred you are spot on. I mentioned in the 1st post that nothing in the drive train of this truck is original. Decoding the rear axle casting numbers shows that it is from a full size (Belair or other) and the axle was manufactured in Dec 1963, so it would have been installed in a '64 model year. Hopefully will get it back onto the frame in a week or two. I need to get this project back into storage so that I can get my daily driver into the garage for the winter!
Mike