You would be miles ahead of yourself to get a second filter houseing (spin-on) installed, and basically a complete second fuel delivery setup (at least to the IP). That way, if something DOES go wrong, you diesel setup is still reliable. This is assuming that you are trying to run veggie (not sure if this is what you are getting at). I recall someone having a sight outlining his two-tank system, that looked to be very reliable. To heat his filter (again, spin-on), he incorporated a coil heat exchanger into his coolant system. This HE was basically 1/2" copper water line, bent into a coil. It looked like a good idea. As for the fuel lines, HIH or HOH is the way to go. Be more specific in what you are looking for, and others here will help you inovate. Good luck!

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1989 300E 144K