Just a quick update-
So those of you suspecting lack of suspension travel were right on, at least partially. I raised the front end up a few turns on the adjusters and that immediately reduced the problem by 30% or so.
Secondly, the car now has the subframe connectors and torque boxes welded in...and that made an even bigger difference. Honestly, it's probably the best change I've ever made for this car and that includes all of the driveline work. Somehow the car feels better in every way- steering, handling, braking, accelerating; the car just moves differently. I should have done this years ago!
So in addition to hitting the bump stops, I believe that the stiffer suspension was just exacerbating looseness in the chassis. Before the reinforcements, all of the vibrations and bumps were making the whole thing jiggle in a very unsettling way. The ride quality is still far from comfortable but it's approximately what I expected with the stiff springs/bars.
Next steps will be a performance alignment, lower profile font bump stops...and possibly a raising up the rear by 1/2". I hate to raise the cg any more than necessary but it's currently on Hotchkis lowering leaf springs and 1.5" blocks. Maybe that was just a bit too much.
