With that much slack, if it's the ball joints it should be visible if somebody watches them while you steer at a stop. You would see the tie rod move but the knuckles not moving. Could also be in the box itself, the rag joint in the steering shaft between the steering wheel and the box, also check the joint at the end of the steering arm attached to the box.
Myself, I'd check that ball joint on the steering arm first. Again, if it's THAT loose it should be easily visible.
My oil line fix
My 100k stopped odometer fix
Brace for impact, I'm in a "modifying mood". Massive thread count inbound.