@Danimal did you ever get to the bottom of this? I just replaced all 4 sway bar drop links ( they were all shot ), inner and outer tie rods on the front ( also shot ), and sway bar bushings front and rear ( you guessed it, shot ). Everything else looks good aside from the rear struts which are clearly leaking - I can't imagine they would be the source of a 70mph steering wheel shake though...
The search continues.
