I'm in the process of swithing engines in my grey market 1985 380se. The engine I have is a clean engine from a 1981 american 380sl (already converted to a double timing chain). I noticed today that there are some differences on the fuel injection. The part number on the 85 fuel injection is
0 438 100 111, the part number on the 1981 fuel injection is 0 438 100 088. The 81 looks like it has an extra regulator coming come of it that has an electrical connector that the 85 does not have. I am not sure if it is smog related or not. My main question is what am I going to have to do to make the 81 engine work? Will I have to change the fuel injection, or is there a way I can make the old fuel injection work?

I did some research through my oem manual and online and I'm going to answer my own question. The extra gagdet on the 81 is a damper that they quit using after September of 1981. The US version of the 380 and 500 from 1981-1985 all used the same fuel distributor part# 0-438-100-088. Some unamerican 1983 380's and 500's used the fuel distributor part# 0-438-100-111, acording to what I found on the internet. My mercedes is an 85, but the engine in it was actually an 84, but for some reason it has the 0-438-100-111 fuel distributor. Due to minor electronic changes from 81-85 with the the fuel injection, I've decided to change the fuel injection because I know my car has the ecu to run it. Plus my car ran really smooth with the odd ball fuel distributor.