My friend Dan came over after work, and we jacked the back of the Scout up, removed the rear shackles and proceeded to install the new, longer ones. This required some attention with a hammer at 11pm as we finished beating them into place over the new Skyjacker poly-bushings. Installation was pretty uneventful.
The shackles did net me another 1.5" of at-rest lift in the rear.. almost leveling out the Scout.
It finally looked like something bigger than 31x10.50s were needed!