If this ZJ has the 4.0L I6 it is most likely a Dana 35, and not a Dana 44A (yes the A is for aluminum). CJ8Ted was correct in that the Dana 44A aluminum center is the weak link, parts can be difficult to find, and there is very little after market support for them. In fact I know of only one company that makes a locker for them (Aussie Locker) and I think they may have discontinued production of those. But just because it has a V-8 (5.2L) doesn't nesessarily mean you have a dana 44A, in fact being that it is a 96, it is most likely the dana 35...that is if it is original equiptment and wasn't already swapped out when the lift was done (one of the most common, and first mods that ZJ owners do is to replace the dana 35, and for that matter the dana 44a, with a stronger differential....either a Ford 8.8 or 9").