You are right on mac,
It's the Mercedes 722.6 transmission, using the same Mercedes multi disk torque converter. Transmission is called W5A580 in the LX's, but its the same transmission since 1996
The 722 series started at 722.0 in 1970. Great transmissions but without mods they are set to shift at redline.
2008 Challenger Silver, all options 8h300590
2963/6400