Almost any mitsu built 3.0 (caravan, 3000GT, Hyundai Sonata, Mitsubishi Diamante) Also, Nate is swapping a 3.5 Gen2 engine into his Gen1. Ive heard that pretty much any Montero with a 3.X motor would mechanically swap over, but then you have to deal with the wiring, so I think that would include a 3.8 Mivec in the last model sold in the US. I also believe OldColt swapped a 3.8 block with 3.5 DOHC heads into his Gen2, so I don't see that being too much more of a deal to swap into a Gen1.

Richard E
1989 Montero - Stock-ish
1989 V6 Auto Raider - 5.3 Vortech Swap.
1987 Mitsubishi Starion 2.6t, soon to be 3.5
1983 Honda XL600R