After that I worked on the "Fuel delivery module". The DEF fill tube had arrived and I modified it so it will work with my auxiliary diesel fuel tank. I cut the entire bottom section off the unit because it was very stiff and difficult to route. Instead I bought some flexible fuel lines for the filler tube and air vent and connected it to the upper portion. One "Fuel Delivery Module" completed.
Where did you source the larger fuel tubing? The DEF filler hose is 7/8" ID but the barb seems big enough for 1" ID.