If I have to replace my rear differential in a year or two which my mechanic says I may need to - I am starting to get a whine out of the differential - possible pinion gear - which one would be best to look for used?

I read other posts that said the 2.88 got better fuel mileage but came out of 1985 300D and 300SD or SDL cars.

I also read that most had the 3.07 differential. I have a 1982 300sd and am not sure which differential is under there. I am not as technical as some of you guys and gals, so please forgive my ignorance.

I have a 300TD wagon whose body is rusted out. Could I use the rear end from it in the 300sd? I am guessing not since it had all the leveling stuff underneath.

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1982 300SD Light Blue
2002 Honda Accord SE
1974 Toro Wheel Horse Tractor
2000 Toyota Tundra Pickup