This particular part number only fits 2017-2019 Super Dutys and will not fit a 2012 truck. Unfortunately, BDS does not offer a radius arm 4" lift for the 2011-2016 Super Dutys. However, they do have radius arms that will work. Give us a call directly at 623-434-5277 and we may be able to put together a customized BDS lift that comes with Radius arms.