I'd check to see if something is loose, especially since you just re-did the front end.
This does NOT sound like shock over-dampening to me. My old WRX setup (coilovers, with dampeners that did a lot more dampening than any shock I've seen available for the B-body [img]smile.gif[/img] ) was overdamped....it was jittery over rough roads, but at LOW speeds. Actually rode decent at 50-80 MPH, but the ride (on the same road, i.e. a chopped up road or freeway) absolutely sucked at 20-40 MPH.