whatever anyone does on hoses..
just COPY the factory Diesel Vanagon hose layout exactly  ..it's more
evolved and subtle than it appears to be at first glance.

  True....but not easy to do, copying the layout exactly...

   My gas inline, when I swapped from the 1.8 liter block to the 2.0
block...I took a LOT of pictures before I removed any hoses....but it was
still like doing a rather large jigsaw puzzle when I went to re plumb
everything....I had two, or maybe three sets of hoses....perhaps about 20
hoses and clamps with various bends, some quite similar but slightly
different....from the Jetta motor, from the Rabbit motor I swapped out, and
from the diesel WBX motor the original swapper must have had at one
time....The 1.8 liter didn't use the oil cooler at the filter, so that was
interesting to figure out....
   After most of a day of trial and error with all those hose segments, I
got everything flowing properly, but boy o boy, I certainly did some
devious routing and splicing to make the segments I had in the cardboard
boxes fit and do the job...