Ok I just went & checked my own 69 Dart & I have the small ball joints. & I have 3 sizes of ball joint sockets.
Snap on S9479A Large
Snap on S9365B Med.
& a third with no marking's & it fits the small Moog joints in my car. The S9365B is obviously for the larger 73-76 uppers & I believe the S9479A is for the trucks.
Sorry for the confusion & hope this helps.