Just, some more information on how Bio Diesel effects the fuel delivery systems.
This effect will also impact ALL diesel fuel lines currently being used, regardless of model year.
The alcohol used to "dry" the biodiesel is the culprit. It eats the volatile oils (compounds that make it flexible) out of flexible components and creates microscopic air holes that allow air infiltration that will quickly result in the erosion of the pressure side of the pump on VP44 pumps used on the 5.9 due to cavitation, and will destroy the delivery valve in the CAPS injection pumps used on the 8.3 from a combination of cavitation and lack of adequate fuel lubrication.
The irony is that purer, 100% Bio-Diesel made with the proper process would be better then the current ULSD fuels, because it would offer better lubrication.