1) Yes, just remove the internal seal and install a yoke without the vent hole.

2) Pushbutton VB's have only have 5 positions, console/column VB's have an extra position for Park. The console/column VB's can be used with the pushbutton shifter and cable but you must use the console/column cable adjustment procedure.

3) Correct, you can update from the 19-spline input by changing the three components mentioned and, of course, the drum. '71 and later have the wide drum bushing so that is preferred.