I am in the process of installing components on my F250 6.9L, I bought a HotFox, and a Dahl heated filter assy. As far as heating the lines... I will recirculate my return line fuel, instead of having it simply dump back into the tank it will be return into the suction line near the tank. Since it just came from the hot IP it should keep things flowing. That combined with me wrapping the fuel lines between the 1/2" coolant lines going to and from the tank (HotFox) I think it will be enough since I have a IDI engine. I also have a return line that connects right after the filter assy.