Back on topic. I have seen engines out of wrecked SLK and C class AMG cars go for as low as $2K. To me, it is just as good to take the parts off these engines and sell the rest on eBay. I've seen it done by a few different tuners (just not on any xfires). The reason I'm not doing this is my xfire is my only investment. I'm in my 3rd year at BSU and only have 4 more until I graduate with a Pharm. D. If I gamble on something like this I could blow my finances for the rest of my education. I have no back up plan, I have to graduate. I'm waiting till after I earn my degree to do anything crazy under the hood. In four years you might see a ten second crossfire sitting in my garage. On the other hand, you might see a broke college dropout with way too much debt begging for a job in chemical research. Nobody can predict the future.

It sounds like you have the time and the finances to achieve this. Go for it and don't let somebody on a forum stop you from sharing your experiences. I know the MB 3.2 can make the power, somebody just has to turn the wrench and get the job done.