Yes, if you look at Autofab's wensite, Ithink they claim 14-15 inches of wheel trav el with their custom-bent TTB beams. Many of the 4" or 6" lift kits have shocks with 14" of travel, so I'd say that's the limit or the max amount you can encounter. my shcosk on the Dana60 SAS have 14" of wheel travel, but I have limiting sgtraps so they don't bottom out or over-extend. Anytime you can get 8-10" travel on both sides, you're doing well for rock crawling with 36-38" tall tires. That's the real killer, even on a Dana44 solid axle like my 78 Bronco has.
If you can let us know what size tire you're looking to run and how hard you want to push the Bronco, we can provide you some more specific info. Both Roadkill and recently pushed our broncos to the breaking point on a big rock crawling event, JSM84