Thanks for the info. I wracked my brain on where that aux fuel port was, but of course, my IDI didn't have one.
I ended up tying into the supply line after the diesel filter head, so that I don't contaminate my stock diesel filter with veg. The veg return line was simple: just removed a section of hose on the back of the motor. I mounted two viton-sealed hydroforce valves for the system i designed (I already had lots of spare HF parts in the garage, and I don't think I'm too worried about cycling heat to install a third valve.) With this van, it already had a rear coolant circuit stock for the rear heater core, so I just bundled my aluminum 3/8" fuel lines with them, and insulated around them. Also, I have a 30-plate FPHE, heated alum filter head, facet pump, and horizontally mounted hotfox in my custom undermount 32-gallon aluminum tank. it's pretty sexy. All i have left is to mount my gauges and switches.
I was able to do this whole install on the cheap, except for the custom tanks. Almost all my parts (except for the heated filter head) i had laying around in the garage.
Not trying to hijack the thread, but hopefully my custom/homemade setup helps others in this forum.