I've got the same bars installed 10-2011 in my 318 automatic 68 fastback. I to could not achieve adequate ride height. I was able to get some longer adjuster bolts and achieve proper height, with about only 1/8" of adjuster length to spare. Now that the bars have settled and been readjusted there is no adjustment left. I have contemplated cutting loose the torsion bar anchor and repositioning.
When I purchased the bars there was no warning on the on the website about not being able to reachieve proper ride height, atleast not that I saw. Numerous emails to there customer support went unanswered, and phone calls were either not picked up at 3pm or I was put on hold until I gave up. Needless to say these were the last product I have bought from them.
All I can say is if you plan on purchasing it's good to know what your getting into.