As long as you are replacing the fuel lines, or even if you don't, replace
the fiberglass engine cover with a metal one.  AFAIK, all of the air cooled
Vanagons had metal engine covers, so if you can find a 1980-3 Vanagon (which
is not owned by a fellow Listee), you can get a metal cover.

If a fire does start, it should stay in the engine compartment, or at least
spread slowly enough that you get a chance to use your fire extinguisher.
(You all do have one of those on board, don't you?)

Keep your original fiberglass cover to reuse when (if) you ever shift into
another van.

We had a 73 Bug with an engine fire, which burned for 5-10 minutes before
the Big Red Truck arrived to extinguish it.  The metal firewall behind the
rear seat kept the conflagration away from the passenger compartment.  After
the engine wiring and all engine compartment plastic and rubber items were
replaced, it was almost as good as new.  Even the smoke smell disipated
after a few months.  It could have used a bit of soot cleaning on the rear
paint, though.

Budd Premack
88 Wolfsburg, etc.
Land of Sky-Blue Waters (and yellow flames)