WARNING: This page is about a different car, the 2016 RAM 3500 HD and 2016 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of CHRYSLER GROUP, LLC
9340 - SAE Fuel Pump Lock Ring Wrench (Originally Shipped In Kit Number(s) 9327, 9327CC, 9397, 9575.)