I won't be doing any engine mods to my Challenger until the SRT team comes up with better shafts (they're supposed to be in the works). The guys modding thier Chargers (with the same drivetrains as expected in the Challengers) are tearing them out from under thier cars on the strip.
No sense in building more HP if you're going to break parts getting it to the pavement.
I'll wait.