i have searched for an hour and a half, and haven't come up with a definitive answer to this question-
do the SLR shackles raise the rear 2", or only 1" due to the fact that it's only used on one end of the spring?
i am looking for a 1" lift, since 2" may put my rack into the concrete girders in my parking deck, which would not make me very happy.

thanks for any help, and to anyone who wants to turn this into a discussion about why AALs are better than shackles.

In my case the 2” SLR shackles which I have run now for a year originally lifted the rear of my X by ~1.5” which is what about most early adopters ended up getting.

BTW I would recommend you always consult with the Manufacturer for the official answer(s) for any questions concerning products they sell