On all the Merc diffs there will be a stamp with the diff ratio. The diffs in the 104 cars are very robust. Able to take 500hp or more. A little research will find the correct diff and cluster match.

Does the car have ASR traction control? Usually it was fitted to cars with the headlight wash wipe and heated seats, as part of the cold weather package. Making sure you have an ASR diff in an ASR car or a non ASR diff in a non ASR car is essential. Everything else is easily fixed...

__________________
David Hendy
'97 Renntech E60RS
'97 GMC 2500 Sub' Diesel
'95 E300D
'88 300TE
'88 250TD
'84 L/Rover 109