SOOO back to the Original question, which was not whether or not this was a good Idea by the way, Are there any special quirks or Job specific tools required to change out motors on a 2004 C class? yes ? No? and if yes what might they be? For instance when I swap motors on a w123 diesel I make a note to myself to verify that I disconnected the Oil Pressure sending line. I missed it the very first time I did it and took a few minutes in the dark to figure out what was holding me up. or all the bolts that hold the motor to the tranny are like 15 or 17mm except the 2 that hold the starter those are hex bolts (forget the size). nice to already have those tools handy when your under there. Oh And I loop a fuel line from supply to return pipes to keep from gravity draining the tank to the ground. the c class is so much more compact and crowed under the hood that there have got to be some tricks to the trade. that's what I'm actually looking for.