It's not that it eats rubber, Biodiesel replaces the bonding agent used in the manufacturing of conventional fuel lines. The fuel will the beging to "sweat" through the line. Just replace the rubber lines with Viton tubing (I buy it from McMaster-Carr, online) and you'll be all set. The first thing I replace is the inter-injector lines, as they usually begin leaking first, and then move to the other lines as the start to soften.
Joe

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1978 300SD
Running Biodiesel/SVO, 2 tank system
127,000 Miles