Difference between the 210mm and 185mm r107 diffs?
 

I'm looking for a new diff for my 450SLC as the one in it is clicking and finding a w123 parts car is easy enough. However if I take out the 210mm diff and put a 185mm do I need to change the axles or driveshaft? Has anyone used a w123 diff in a r107? The reason I am bothering to do this is I want at least a 3.07 if not a 3.46 rear end. The taller ratios are easy to find in a 210mm housing but would make the car into a dog with a 3 speed and 4.5.

The 185mm diff was used in 280 SL/SLCs.
The 185mm diff is narrower than the 210mm, hence, the axle shafts are longer. Axles from 114/115 & 123 chassis should be usable.
The 185mm diff uses a smaller flex disc. The yokes can be interchanged.

I'm pretty sure the 210 diff was used all the way up into 2010 ish and could be found on rear drive Chrysler stuff that tended to use higher number ratios. However, I don't know if the internals will interchange, ( the external parts are going to be different. )

I seem to recall that there was some sort of " Reinforced " and standard version of a certain older MB to compound difficulty in mix matching parts.

Post this in the Performance section as others have swapped diffs around before.

Thanks guys. Looking into this further I'd need axles, the diff, and possibly the last section of the driveshaft. Similar to a diff upgrade in my 190. I'll keep my eyes open for a 450SL parts car and see what I can take.