This leaf helper spring is designed to match the fit and function of the original spring on specified vehicles, and is engineered for durability and reliable performance. This part is compatible with the following vehicles. Before purchasing, enter your vehicle trim in the garage tool to confirm fitment. [Ford E-550 Econoline Super Duty: 2002] - [Ford E-550 Super Duty: 2003] - [Ford F-450 Super Duty: 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016] - [Ford F-550 Super Duty: 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016]