I have had a '02 and a '07 Endeavor. I have lengthened the diesel generator pickup on both. I am not sure which chassis you have but hopefully the fuel fill door panel can be opened easily. On the top of the fuel tank the generator fuel line is the smaller of the lines. remove the hose and then screw out the pickup. My '02 was a steel pipe and the '07 was a plastic tube. If you get this far take some measurements on the tank and adjust the length of the pickup accordingly. Keep in mind when dry camping about the modifications you have made.
2007 HR Endeavor 40PDQ