Deep under all that crusty grease you will not find balljoints, you will find king and link pins. Unless, of course, someone has installed a Bay beam on your splitty. Basically, if you have balljoints, they MUST be Bay parts.
The things that look balljointish are the tie rod ends and the drag link ends. They may or may not interchange with Bay parts. When I've bought drag link ends, I've had to buy the link as well, and I'm pretty sure the whole assembly (ends and link) is different. The tie rod ends may be available separately from the rods and there may be some interchange there.