Part Number Location

Okay guys, have a question, where on the drive line is the part number? Its not on the ends, those numbers are the yoke number. But according to my wide assortment of books, parts manuals etc. they do have a part number, but none tell you where to look.

Reason I ask is I have the driveline for the dart but I also have the drive line for the Super Bee. Both are 3 inch, both have the 2 5/8" space between flanges, granted one has a more petrified road/oil/grease look.

Can you help?
Gman