The number is not an engine number. The sequence looks like a part number but is not in the US system. The part numbers for complete engines, short blocks, and crankcases all have the key number group 010 not 011. This makes me think the number is just a casting number.
The important features of 240Ds are where the oil filter is and what type of glow system. Otherwise they are pretty much interchangable. A/C mounting is also built onto the block after 1979.
Bosch Master, ASE Master, L1
33 years MB technician