IIRC Mitsubishi didn't recall the crank bolts on the 1989 models. They issued the recall for a later year. Even though they used the identical crank bolt in 1989. So, even though Mitsubishi never issued a formal recall for the 1989 crank bolts, it's best to replace them with the newer style.

Mitsu # 6 - 98 6G72 Montero Sport, Locking Rear Diff, Aisin Manual Hubs, 31x10.5

Mitsu # 7 - 02 6G74 Montero Limited