It's not uncommon, however, to see a guitar with two EMG 81s in both bridge and neck positions (for instance, Kirk Hammett's  EMG-KH21 pickup sets, which include two EMG 81 pickups for both neck and bridge positions).
While not standard practice, some guitars are equipped with two EMG 81s in both the bridge and neck positions (as seen in Kirk Hammett's EMG-KH21 pickup sets, which include two EMG 81 pickups for both positions).