Gear ratio change in 4spd V6

[MG7]

Hello. I was wondering if there is a way to program a 3.90 rear end into a 2009 charger 4spd. My friend has the predator for it but can not find the option. Is a change possible? He is currently running version .9r07. Thank you.

[Mike_Levy]

Doubtful. CMR may be able to do it, but theres no 4 speed support in the tuners at all.