This was the first car we installed the 3.90 ratio rear ,now we have another and this one is a modified srt6 ,,will be going to a drag strip soon as the track opens in Wisconsin and my car will have a 3.90 in it soon, and will also run at a track.
this is a bolt in mod, you get the differential, open gears),TCU and the bolts that make the change,, the srt6 requires one extra part ( yoke part)
the cost for the limited is $1599.00 for the srt 6, $1799.00 ((price as of April 2022))