Hemi Alternator Wiring
This article
Gears Magazine - High Output: A Look at Today's Charging Systems gives some helpful info on why the manufacturers have gone to PWM control.
The install of the driver was easy and it works as intended allowing me to control charging with the external regulator. Not sure what years are impacted, but their website shows starting in 2007. The 6.1 I have came from a 2010 Challenger.