I have a low mileage M104 engine and transmission [from a 94 E320, 106K miles] sitting on the shop floor, and a 92 300E / 89 300CE that have a tired engine / transmission [respectively]. Does anyone know if or how interchangable the M103 [3.0L] engines/transmissions are with the newer M104 eng-trans ?
I suppose the engine ECU and under hood wiring harness must b different, but how about the rest [physical dimensions]?
Will the transmission fit, etc? Any expert insights will be appreciated.

 

depends on transmission number.

tell us the first 6 digits of both.

 

the 104 and the 103 block are pretty much the same. how ever i would not be trying to exchange the motors and trans there is way to much other stuff involved like ecu harnesses stuff like that