Long story short I want to swap in a 2009-11 SLK350 RWD engine into my 2008 C300 4MATIC. Aside from the differences below, and some other changes, the motors are identical (the 300 fits in the SLK, 350 272hp in the W204 etc.).

I was already expecting to have to swap oil pans for the front axle which I know can be done. However now I'm seeing different placement of the starter motor and some other nuances between the W204 RWD and 4M M272 applications. Does anyone know if converting a RWD M272.969 to 4Matic is possible and everything just bolts on? Or are the blocks different? "Attached components" sounds like it's possible but I'm not sure how you'd move the starter motor on a different block.

 

Same block