Yes, just having the trac-lok in the rear axle will help you out, whether in 2WD or 4WD. Think of it this way: with an open rear and front axles, you realy have only 2 of the 4 wheels driving your rig. Any traction aid in the rear makes it 3-wheel drive when the t-case is in 4hi/4lo, and a traction aid in the front axle too makes it a true 4wheel drive. There is some major difference in driving on snow, ice or slippery surfaces, so that should be a major consideration for you in AK.THe ARB air locker is the cat's meow, but will run close to $2000 for both axles and the air compressor, depending on the labor to install. I've rode in a few rigs set-up with the ARB's, and have only heard of one breaking due to the owner not torqueing the ring gear bolts on a scheduled basis. I prefer a full spool since 90% of my driving in the Broncos is off=highway, either on gravel roads or in mud. It is much harder on axleshafts and front axle u-joints. I run the factory limited slip rear only in my 98 Z-71 and 06 Dodge 4x4 daily drivers, which only see 50% offroad, mostly mud. Having an open front axle on these trucks has gotten me in trouble whenever on an incline, since the wheel on the low side spins and gets all the power.
JSM84