I have a good running 84 van with a 92 Jetta/Golf/Rabbit 1.8 liter motor.
It's mounted using diesel vanagon parts (the same block) and I am running a
5sp manual tranny.  This has been a great set-up for me so far. (3yrs and
appx 50k miles for me, bought it as is..)
  Today I bought a second motor, a 2.0 liter ABA Jetta motor..a 94 with 125k
miles on it, complete for $100 off Craigs list.  They usually go for around
$250-$400.
  My planned project is to pull the 1.8 liter and swap on the bottom end of
the 2 liter motor.  The 2.0 liter ABA is supposed to put out about 25 more
ponies and I am told they are better designed for lower RPM running with a
forged crank and some under the piston oil squirters.
  I'll take some pics as I go.  Should be able to do it in a day, once I get
my aftermarket distributor clamp in the mail.  The reason for swapping on my
1.8 liter head is the 2.0 liter has a 'cross flow' intake, which wouldn't
fit under the decklid...but the 1.8 top end bolts right on, and my current
head has a nice aftermarket cam already.
  Very inexpensive way to power a Vanagon.   I've been shopping the inline
motors, mainly just for fun as my current one is still running fine, but
when I saw the $100 complete motor...Hadda buy it.  I can re-sell the head,
the water pump, the alternator, the distzy, etc and actually make money on
my swap while getting some extra HP...Shoot, I have to pay almost that much
to fill up my F-250 Ford diesel pickup every time I get fuel..
  That is the plan anyhow.
  Don Hanson