I thought that for ice you wanted an open differential, being that with an open differential it wont force your tires to slip, conversely, if for some strange reason, you get stuck and need a locker to keep that one tire from spinning alone, it could be nice to have a locker. I say that an ARB is gonna be what you'll want for that, (disclaimer: I dont know about any other lockers like which ones will "ratchet" on the street acting like an open differential)
Joe Funk
Portland Oregon
82 FJ40
65 FJ45
90 FJ62
FJtoys@aol.com