OK I'm still searching on this but again I'm at a loss... here is the info from this site


All trucks 79-96 came with what Mitsubishi would call a 8 inch differential in the rear

GEAR RATIOS
D50/MMs came with 3 different possible gearing options
3.545 used in certain 2 wd trucks let you achieve optimal fuel mileage
3.909 most common gear ratio used in about our trucks most 4 X 4 came with them for sure
4.222 rarely seen in the D50/MMs only seen so far in 4 X 4 so far primarily seen in Dodge Raiders/Mitsubishi Monteros
4.625 never came in the trucks only seen in the Monteros/Raiders swaps into our housings

LIMITED SLIP DIFFERENTIALS & IDENTIFICATIONS OF THEM
LSDs or different gears can be swapped out of various vehicle depending upon which diff you have if you have the 7.5in diff a rear diff
out of any FOUR CYLINDER MM/D50, Montero/Raider will work

If you have a LSD factory you will have an orange sticker in the door jam and on the differential housing its self talking about the use of LSD additive inside of that housing If you cant find those stickers but still wanting to make sure you do or don't have an LSD you can jack the back of your truck up and spin one wheel then watch the other side to see if it spins in the same direction

Now if you have a 4 X 4 MM/D50 the rear differential out of a Starion/Conquest will work Starions 1983-1987 (1986/87 wide-bodies all came LSD, narrow-bodies with LSD are more rare) used a 7.5" diff, which will work in the FRONT of a 4cyl truck/rig. Starions 1988-1989 used a 8.0" diff, which will work in the FRONT of a V6 truck/rig. (thanks Robert) If you have a V6 powered truck any first gen Montero/Raider with a V6 will change differentials with your trucks 2nd generation Monteros wont work with the 8in housing available in our trucks I was told the Monteros have a high pinion design compared to the trucks low pinion design

---keRby
mopar_1986_power_ram50


The Starion LSD from years 83-87 will fit the front diff of the 4cyl MM/D50 trucks/Monteros.
The Starion LSD from years 88-89 will fit the front diff of the 6Cyl MM/D50 trucks/Monteros.

The Montero LSD from 83-89 4Cyl will fit the 4cyl MM/D50 trucks rear diff.
The Montero LSD from 89-91 6Cyl will fit the 6cyl MM/D50 trucks rear diff.

Not all early Starions had LSD, special order and 85.5.
All wide-body Starions had LSD.
Not all Montero's had LSD, check for orange sticker inside drivers door jamb.

Kane
MainstreaM


just to clarify no truck or monty has a 7.5" rear diff.only the front is a 7.5".the rear is a 8".the 4 banger monty and the v6 has a 8" rear for the gen 1.the early years 7.5" starion lsd can be swapped into the front 7.5" diff,with a spacer.



so I read this.. a few times and I'm just dumbfounded by it... I did the formula 336 x 60 x 3.909 / tire = rpm to work out differences in tires and rpms using different gears.. coming to conclusion that the 4.625 should do pretty decent in my 2.6 4x4 with 33" tires...

OK... now the info I'm completley lost on is what I need.. I hear the words... "gears" "ring and pinion" "differential" "gear set" "pumpkin" blah blah blah ....


All I want to know is what to buy .. I think from alllll the reading that it HAS to com from a 4 cylinder montero

"The Montero LSD from 83-89 4Cyl will fit the 4cyl MM/D50 trucks rear diff."

... I've not found a single 4cylinder montero with an lsd and these gears??

and... not a single thing is mentioned about front gears except lsd from the cars... I just want the gears so I can use 33" tires without killing to truck... lsd in the rear would be nice but up front I don't really care.. I'll occasionally play in some mud nothing too major...