What do you do about a ball joint nut for an 87 Chevy striaght axle that still moves after tightening it to finger tight like the instructions say?

I may be wrong, but I don't know of any 87 Chevy with a straight axle. Ford trucks are all that come to mind. Anyway, Ball joint. making sure we are talking about the same thing. Top and bottom of the spindle behind the tire and the brake rotor? These bolt have to be more than "finger" tight. It would be hard to put too much torque on them. Don't have the specs. on this, but pretty much everything you could do with a 1/2 inch rachet, or an impact.