@ dfreem01: For your V6 Raider, you only need to install the pumpkin from the 91 source axle, not the entire assembly. This is a direct bolt in, no difference in the axle housing. Make sure to use gear oil with the traction additive, otherwise your new LSD will not work well.

You may also consider the 92-93 SR rear axle, these have disc brakes, 4.625 gears, and LSD.

@ BlueMont: Based on all the threads on this topic, I've not read anywhere that the gear sets are interchangeable between the old school square Montero and the much later tech in the Montero Sport. Based upon the normal life cycling of engineering, they are not likely to interchange. As the MS axle is a drop-out, you should not have difficulty locating the 6.636-geared LSD pumpkin using search engines like car-parts.com and others.

If you need to mod something, put some leaf spring mounts on the 94-97 (ish) Montero axles and just go full boat with the 4.9 gears and air locker. Find some 4.875 gears for the front diff.