I had a '91 Montero...
I loved it! It was dependable, drove and handled well, and was a pleasure to own. My only complaints were about the price of parts as Mitsu typically modularizes components. Instead of simply replacing the bearing in the serpentine belt idler pulley, for example, you have to replace the entire assembly, bracket, pulley, bearing, and mount included. So, the price is $50 instead of $5. The good news was that there were very few parts issues.
At about 110k miles, the engine started using oil, and the consumption worsened quickly up to about 130k miles when I traded it off. A new engine was VERY expensive. An overhaul was also VERY expensive. I doubt you'd find many used engines, or long blocks as there arent' nearly as many Mitsus on the road as Toyotas, for example.
AIR 2053 Current: 2006 Born Free 32 RQ Kodiak Chassis, & 1995 Coachmen B-van
Former Airstreams: 1953 Flying Cloud, 1957 Overlander, 1961 Bambi, 1970 Safari Special, 1978 Argosy Minuet, 1985 325 Moho, 1994 Limited 34' Two-door, 1994 B190 "B-Van"