The good thing with the 2011 is that you already have the 8.8" rear end, and the 3.7L V6 has a little more power than the 4.0.I'm very interested in what people are doing with their v6 S197 Mustangs. I have a 2011 that I took to the track a few times last season to do some bracket racing in the 12 seconds and slower class. I'd really like to connect with others that are or want to bracket race these cars.
The good thing with the 2011 is that you already have the 8.8" rear end, and the 3.7L V6 has a little more power than the 4.0.
But most of the 3.7 cars were given a 2.73 rear end for gears so very slow getting started, but it improves the MPG. Get a tune from MPT which seems to have the best option for the 3.7, and maybe a 3.55 gear change in the rear end. I wouldn't go with anything more than 3.55 based upon the transmission - a 3.73 or 4.10 makes 1st gear pretty much useless and short shifts you.