The family line of the 3.2 V6 that is under the hood of both XFires.

Knowing this information may be helpful if you can find any HP gains to be had by swapping engine parts... (such as heads)...
back in the days of muscle cars we would take the heads off a 351 ford block and bolt them on to a 302 engine block. I'm not speaking of Cleveland's or Boss engines, but they also had engine family orders such as - a 390 block was the same block the 428 Cobra Jet engine was built upon, so you could maybe use the heads from the Cobra to hop up your 390.

You all get the idea, do some reading and comparing, you never know what combination of engine parts you may find in your local yard. hooah

3MBXV03.2LBI Mercedes-Benz: SLK32 AMG Kompressor; C32 AMG Kompressor
3MBXV03.2LBX Mercedes-Benz: SLK320
3MBXV03.2LBX Mercedes-Benz: CLK320 (Cabriolet)
3MBXV03.2LXX Mercedes-Benz: C240 (Wagon), C240 4Matic (Wagon), C320 (Wagon)