>>>1.  needs a bigger fuel tank, cruising range is too low.

IF you do 2 and 3 you get more from what you have.  Plus there is an
aftermarket tank for @22 gallons for $600

>>>2.  needs more power

You can transplant and go through the hassles

(YOU have got to wonder WHY the transplanted Vanagons are NOW for sale???)

OR you can do a few changes to the WBX and have some more power to a LOT
more power.

>>>3.  needs a five speed (OD top gear) to get the rpms closer to 3000 at 70

mph rather than 4000+.

Weddle sells South African .457's for $2K, drops the rpms by @~600 rpm, or
rebuild and add a .457 ring and pinion to drop the RPMS BUT ADD SOME
POWER!!!

>>>4.  Needs a better ventalation

Yes, The noise is annoying.

Speed costs MONEY, how much do you want to spend???