For all 2010 to 2013 Ram 2500 4x4 trucks, and 2010 to 2012 Ram 3500 4x4 trucks, stock height and lifted.  We do not recommend short arms for trucks with more than 5" of lift, however you "can" use them up to 7" if you are willing to have poor ride quality.  You will really benefit from long arms if you are above 5" suspension lift.