Going strictly from my past drag racing experience, and running different tire hights on cars at the drags (with automatic transmissions). I firmly believe an SRT6 that's currently running around 12.20's, would probably be able to break into the 11's with a rear end swap, and drag radials.
I think a NA's 3.27:1 rear end, and the use of at least 1" "shorter" DR's than the stock hight tires on a Crossfire would perform very close to what a Crossfire would do with 3.54's.
The Automatic transmission can deal with nearly any rear end gear change no matter how low 1st gear is. Now if we were talking about putting 3.73's in a 6 spd, then 1 st. gear would be practically useless.