I bought the ball joint kit from powerstrokeshop.com. It comes with Moog upper and lower ball joints plus all of the seals. I have several wholesale parts accounts here in town and still could not beat the price. The upper grease zerk will not have turn clearance. I greased the upper ball joint then removed the zerk before installing the yoke. When I grease the chassis, I remove the front wheels, remove the upper ball joint plug, and reinstall the zerk to grease the uppers. It's a little tedious, but at least I know that they have grease in them.
Powerstrokeshop.com