Well, here is another M156 / 63 AMG supercharger setup. This one comes from Xtra Power (creative name, eh?) who we have never heard of. There are no boost numbers or pricing details given. The only details provided are that this puts out 660 horsepower with 595 pound-feet of torque and is available for all 63 AMG models. They also state that more horsepower is available with aftermarket cams and headers although no details on their cams or headers are provided. Is this legit? We do not know, but the forced induction scene for the M156 sure is heating up.