Hi, I recently did this and yes you can use a 3.0 mini van motor. You will need to do the following.
1. Get a Montero oil pump
2. Plug FWD dip stick hole in block
3. Drill hole on opposite side(There is a casting mark for the dipstick.
4. Use the Montero motor mounts, you will need to seal the drivers side to prevent an oil leak.
5. Use the Montero oil pan and pick up
6. Pilot bearing is on the flywheel
7. Use everything else motor related from your Montero, everything bolted up for me.
8. The mini van cams will be different, you can swap out the cams if you want to.
Take your time and good luck.