For the 4-cyl Montero / Raider / Mighty Max / D50 models, there are some factory pieces that can be maneuvered around...this is specifically the disk brake, leaf spring rear axle from the 1997-1999 Montero Sport....a direct bolt in piece. The use of this axle open the 4-cyl model up to housing the 9" ring gear bits that included a hybrid locker / LSD on the post 2000 Sports, factory 4.90 gears, too.

For the front differential, the 8" front V6 Gen 1 diff is a direct replacement, and ARB & others make things for that pumpkin. I have this diff set up with a Starion LSD, even.

Lastly, while pulling apart Sports for better use, grab the 2-piston front calipers and 315mm rotors from the models equipped with 16" wheels.l