It shouldn't move up or down much at all. It's fastened to the steering box's pitman arm & the idler arm, both of which are fastened to the K member. The K member doesn't move. The only up or down movement would be from the slight arc that the two arms swing in.
The drag/center link is really not supposed to move up and down. If you are feeling up and down movement, there is either looseness at the idler arm or pitman arm.
Thanks, No I have nt felt anything as the car does not run, I am trying to move the motor farther back to help with weight transfer I plan to race the car. Thanks for help I really needed that information because I wanted to make sure larger than stock oil pan clearence would not be a problem.