I have a 2007 C230 with a balance shaft problem so would like to swap the engine rather than fix it. I found a 2009 SLK 350 with the M272 3.5L engine. Given they are both the M272 engine design, I believe the fit will work. Assuming that is correct, my question has to do with the ECM. I assume I'll need some type of software upgrade to the 2.5L EMC to get it to run the 3.5L engine. If that is correct, anyone had experience with this and can give some pointers on how to get it done? Any other gottcha's I need to think about?