Installed a GV in 2009 when this Hemi Duster was built. I would do it again, a simple toggle on the right front of the bucket seat brackets engages the overdrive for highway (over 55mph) driving.
29.75" tall rear tires / 4:30 gear / 2450 rpm @ 65mph....the sweat spot. The split shifting isn't for me, but the OD goes good with power steering and A/C.