I think the clear lines as well as the blue hard plastic lines under the car are Nylon and Biodiesel compatible. What the the short sections of black rubber lines that connects to the hard plastic lines? Are they Biodiesel safe also?
Id be more worried about the seals in the pump.
I'm not worried about the IP. I already replaced the distributed head o-ring with a Viton one. If I find a leak, then I'll pull it and reseal it. I'll also replace the return lines with Viton. Back to the original question.
most of the rubber lines are probably not compatible. better find someone that has WVO'd a bunch of these rides and ask them...
Conventional wisdom around the backyard
biodiesel folks in my area says that
the IDIs all need their rubber fuel lines replaced,
and TDIs are do not.
Also, they say that it wont fail catastrophically,
but begin to weep after a period of time.
I went through some stress to find Viton - insert fuel lines,
in hopes that I will one day have it on bio.
I found a local hose company who sold me 5/16" viton-insert
B100 compatible fuel hose for like $6-7 per foot.
I was unable to find the smaller sizes needed for the return line, though
(Both Injector return lines, and return from pump to body lines)
There are plenty of places online selling B100-comp fuel hose kits for IDI,
IIRC $100-140.
-Brad