Clutch throw out bearing?

[eric67m]

Below is a picture of my clutch and pressure plate that came in my truck with a sm465 transmission. The second picture is of the throw out bearing that came in my truck (left) and what the auto parts stores show as the proper replacement on the right.

Which is the proper throw out bearing for the clutch in the picture? My old one rattles and I would like to replace it but not sure if I need to search for the long style one that was in my truck or the other shorter, more common replacement.