Govt. paid Admin.
Join Date: Feb 2003
Location: N.E. WA
Bronco Info: '95 XLT, 5.8/E4OD/MassAir/6" lift/4.56's/35x12.5 BFG AT-KO2 or 33x12.5 GYW Duratrac
I don't think you'll like a lunchbox type locker in the rear end. lunchbox style locker generally refers to the type of locker that automatically engages when the two wheels start to turn at different speeds. they can be unnerving with the clunks they make and handling while cornering on the roads is less than ideal. I have a lunchbox style (Aussie) locker in the front of my '90 FSB and while it is awesome traction for getting me through damn near anything, it's clunky and noisy and even effects my steering a bit when the hubs are locked, even if not engaged in 4x. The same rig had one in the front and the rear but the previous owner pulled the one in the rear for the reasons I gave above. All that said... they are cheaper by far and nearly bullet-proof. Great option for an off-road dedicated or mostly off-road rig.
Electric and Air type lockers offer much better control but cost accordingly. They will only be engaged when activated (by electric or air pressure) so you only have them engaged when needed and not "whenever". Air lockers are great, if you have on-board air, but that's a whole other supporting setup you need to install, so the electric is probably more cost effective and simple to setup.
Ideally... I'd like a Limited Slip rear end with an air locker in the front (w/on-board air) for my limited off-road and daily-driver, on-road use.
I've only ever had the lunchbox style in my '90 though... so what I've shared above is just from reading threads over the years. Someone with more direct experience will hopefully correct me if I'm wrong.