If it were my car I don't know if I could justify having that motor just for the sake of having a V8. My suggestion would be to drive a CLK430 or something with that motor to see how it behaves. It could be a lazy V8 with a poor rev band and you could inadvertently make your Crossfire into a GT car. Not to mention the weight you'd be adding to the front end for a modest bump in horsepower. While more expensive I'd try to get my hands on the new Pentastar V6, light and powerful, 292 HP.