I bought this new lower ball joint at a swap meet a few years ago without a box. I think it is a '65-73 C-body ball joint. Has 5/8" threads and 65 near the grease fitting and 24-4001-026 on the steering arm. Here is picture of it with a typical B/E/late A ball joint below. What is the difference between a '65-73 Imperial ball joint and a '65-73 C-body ball joint?