This is the larger version of the rear hatch lock that became standard after 1984. If you have an 84 take a look at the lock. If it is flush with the hatch and you have to push it in and it is about the size of a 50 cent piece then this is the lock you need. If you it is more like a button that sticks out then you need the earlier version that was used from 80-84. This is an aftermarket lock with two keys. You may be able to use your old lock cylinder from your old lock to key this alike to keep all of your keys the same, but this lock cannot be rekeyed as the tumbler is different than the original. So you would need to see if you can swap the entire tumbler.
Also this lock doesn't have the provision for the power lock mechanism on it so if you have that and really want to keep it, you can't use this lock. However if you want to eliminate the power rear hatch lock and just lock and unlock the rear hatch with the key (never get locked out again), this is a good way to go.