There will be an orange sticker on the doorframe for an lsd warning if it has one, and often a sticker on the back of the pumpkin. No factory front locker available. THere is a fitable rear air locker from a 97-99 Montero SPort available, but very rare, that should be a bolt in with a couple of tricks. Depending on the size of your front diff, some Starion lsd's may fit with a ring/pinion change.

Not responsible for advice not taken...