Not a dumb question at all!  I have always thought about putting a spare tank
under the van, either in the spaces beside the frame or in the big cavity
over the transaxle.  I keep an eye out for cheap alternatives.  One of these
days I will check out a farm supply store and see what they have.  I think
any reasonably strong tank would work, just put a hose from it to the fuel
pump, add a tee fitting and a valve.  Piece of cake or piece of crap?  Who
knows.  I do agree that having even a couple extra gallons might come in
handy on a long trip in the middle of nowhere, and I hate having a can in the
vehicle.

Anyone done this or something like it?

Bill Marshall
85 GL Tiico
PHX AZ