Ok, I am working on a 240z street car for a customer. There is what I would swear is a bad pinion bearing. I took it apart and I am not finding what looks like would cause the noise. I have lots of Differential experience, but have never had one of these early Datsuns apart. Is there any other bearings ie wheel or trans that can cause a similar noise? Where do I get bearings and seals to rebuild the unit that is in the car? it's a '72.

any help much apreciated!

Thanks