The M275 V12 has a completely flat curve from 2100rpm to about 4400rpm. Derestricted it would probably peak at about 3000rpm, but the torque is limited as there's no 5G-Tronic auto box that will take more than the 1100Nm of Brabus' version (note that's only about 56Nm more than stock). If there was any Mercedes box that would take the torque, it probably wouldn't be long until someone built one with in excess of 1600Nm. HP-wise, the 'stock' AMG 6.0 is good for 612hp, while either the 6.3 stroker or Renntech's improved ECU will push it to 730hp+. The Chrysler ME412 used the M275 with increased boost and probably an improved ECU, making for 850hp (and a bespoke Ricardo transaxle to hold the torque). Combining all three would result in a motor of epic proportions, in a CL65 it would be one of my dream cars. Even stock, it's just about the most excessively opulent engine since the old M120 V12 was stroked past seven litres.