Since I just recently was under my own car with all that apart I know exactly what you mean by your descriptions.
Do check the other side as mentioned above, because I was so busy being a smartass I didn't think about the possibility of the K frame being off to one side. (That's possible) (of course as mentioned above, bent or broken control arm pivot pin could do it also)
As far as the noise when you hit a bump, you might chk both ends of the shocks also, as a loose mount or missing grommet can make a hell of a noise when they move.
DOH, just saw your post.
William was asking about side to side movement of the K frame, not ride height.
Chk those big bolts holding the K frame in.
Since you said the mark looked older on the other side, the whole K frame could be shifting side to side.