I need to replace my upper ball joint. The ball joint I got is four sided with threads but the one on the truck is round and looks pressed in. the truck is a 1990 D250. When I went back to the parts house the only other ball joint they showed for the truck was smaller but also four sided and threaded.
Any ideas on what ball joint I have and where to get another one?

 

I think you have the right one. Check the plate on the drivers door pillar to see if you have a 4000 lb front suspension. You need a ball joint socket to remove the joint. I got a kit from Advance Auto Parts in their loaner tool. I think the plate will read something like 3800 lbs. Good luck.