i would go with a factory locker high pinon diff. you can order them from marlin or a toyota dealer, or you might be able to pull one off a landcruser down there. not much more $ than an arb, and it seems to me, a lot less to go wrong, especially with a cable actuater. i would be a little nervous of deep water crossings, whitch i'm sure you have alot of, with the electric actuated factory locker. with a high pinon , you also get more clearence on the 3rd member and better driveline angle and clearance. just some thoughts. fritz