Those I6s were made for years and years and years. They did update it in 1997 to a "high output" version (like 20-30 more hp IIRC), but basically any Cherokee 4.0 will fit in there, but you'd have to worry about emissions. Those are also very simple engines...when you say the "engine went out" what do you mean?

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth