Read suspension Help

My 8 just feels squirrelly running over man hole covers , rough patches of road . In Nascar terms lose ! If I am in a curve read will go outward . I am talking speeds at 40 45 MPH range !

I am going to jack the rear end up ...what should I be looking for ???

I do the push down on car shock test and she sits right back up .

I looked at the bushings and all seem to be in place .

:dunno:

Thanks