I have personally tuned many of the SRT-6 Crossfires and I can assure you that they are faster than my tuned 135i.
12.2 @ 115 is what our shop SRT-6 can run all day. Upper 11's is the fastest we have ran.
My best in my 135i with my mods is a 12.6 / 12.7.
www.letmotorsports.com
Stock for stock is a drivers race.