We've had this discussion before and you should check a bit closer because USA 4.5's have 3.23 diffs and only USA cars.
From the 1968 service manual 108-113 cars.
280 S/8 108.016 auto trans K4C025 up to may 1969_______3.92-1
280 SE/8 108.018____________________________________________3.92-1
coupe 111.024____________________________________________3.92-1
cab 111.025____________________________________________3.92-1
Any of the above with Four speed trans G76/27___________3.92-1
Five speed trans G76/27-5_____________4.01-1
---------------------------------------------------------------------------------------
FROM MAY 1969
Auto trans and four speed manual G76/27 or K4c025___________3.69-1
Five speed manual trans G76/27-5_______________3.92-1

---------------------------------------------------------------------------------------
280SL/8 up to may 1969
113.044 G72 or k4A025 o4r ZFs5-2_____________________________3.92-1
300SEL/8
109.016
----------------------------------------------------------------------------------------The above with G76/27 0r K4C025 from may 1969_______________3.92-1
G76/27-5_____________________________ 4.08-1
---------------------------------------------------------------------------------------
280 SL/8 from may 1969 4 speed or Auto___________________3.69-1
5 speed__________________________3.92-1
---------------------------------------------------------------------------------------
300SEL/8
4 speed or auto_____________________3.69-1
5 speed____________________________3.92-1
---------------------------------------------------------------------------------------
280se/9 3.5
cOUPE 111.026 4 speed and Auto _________ __________3.69-1
5 speed____________________________ 3.92-1
Cabrio 111.027
---------------------------------------------------------------------------------------
300SEL/9 3.5
109-056 4 speed and auto___________________3.69-1
5 speed___________________________3.92-1
300SEL /8 6.3 Auto only____________________________2.82-1
---------------------------------------------------------------------------------------
280SEL 4.5
108.068 \\\\ 5-71 to 12-1972 _______W3A-040 trans______________3.23-1
108.067
109.057
later production run __________________________________________3.27-1
___________________________________________________________________________Euro delivery 280SE/8 3.5
108-058------------------------------------WK4A040 -------------------------3.46-1

I was going to send you this privately to spare any embarresment,but seeing as you have message thing blocked I will post it here.
note on several forums you insist on saying that the 4.5 only had the 3.27-1. I've seen a few 3.23 diff sets so I know they exist outside the US. In future you will do everyone a favour by posting correct info as incorrect info doesn't do anyone any favours.

note on several forums you insist on saying that the 4.5 only had the 3.27-1. < and you should check a bit closer because USA 4.5's have 3.23 diffs and only USA cars. >>


Save yourself.....
We have known for years about that info. But we could never verify it b/c
ALL USA .067/068 we have ever done were 3:27..and we have proven such by reading the ratios right off the cases on so many it is not funny.
How much CLOSER do you want us to check??????????


Now, if you have personally seen a few 3:23 on USA Versions , I will not tell you to look closer or doubt your readings..... but don't tell me that all the ones I have meticulously checked the ratios on are incorrect.

Get rid of the attitude.

Thanks for all the info! The gears are turning...

...and Arthurs teeth are Grinding....
Good luck with it!

I have had several 280SE 4.5 cars, and they all had 3.27:1 rear axles. I have successfully installed one in my 220SEb fin with its original manual transmission. The car is a little more sluggish, but the engine turns at lower RPM’s at any speed, and much more frequent gear shifting is required.

It isn’t worth arguing about weather the w108’s with the 4.5 liter einging came with a 3.23:1 vs 3.27:1 rear axle, as the difference would not be noticeable.

Incidentally, the M180 or M127 engines in the fins can easily handle the RPM’s required to cruise at 90+ MPH all day long, if they are well-maintained. It is better to rev them high than to potentially lug them with a rear axle that is too low.