Power steering box input shaft adjust

If I understand you correctly;
You cannot adjust the"freeplay" out of the column side of a Chrysler Power-steering box. It has to be there to activate the control valve.
With the engine off, what you are seeing is the flexing of the reaction discs.
After the engine is running, that flexing is what signals the control valve to start boosting.
With the engine running, a lot of the flex disappears as the oil-pressure inside the box increases.
If you want more or less boost or just to change the boost-timing, you have to take the box apart and add/subtract more/less/or thinner/thicker discs. I used to get those discs at the Mopar dealer.