re:  Increasing the power of the stock VW T1, T4, Wasserboxer, Inline
4s or 5s or 6s or 8s engines has been going on for many years

This is very true but what is missing is that (I bet) 95% of the time
power increases available in the aftermarket provide the newfound
power at higher engine rpms, often at the sacrifice of low rpm
driveability.  Given that Vanagons are really pretty big trucks and
not likely to be able to use more power and speed where the road
becomes curvy, this seems a little useless.  In addition, Vanagon
owners have few options when it comes to changing overall gearing to
match the new found higher rpm capabilities.

It seems to me the best improvement for a Vanagon is not a "screamer"
engine but rather just a bigger one.  What currently seems best to me
is the VW/Audi 5 cylinder in Eurovan tune.  Probably something really
close to what VW now offers in South Africa.

Also, while everyone is different and can do what they want, it just
seems more likely someone would want to own a high performance Beetle
with a screamer engine than a Vanagon set up like that.  (Heck, the
Beetle can stand really big rear tires to get the gearing, and
probably different gears are actually available too.)  Vanagons are
just utility vehicles and will never outrace even a 4.3 Chevy Astro
Van or such unless they have the same engine (he'll be gone by the
time you get your rpms up) and who cares?  Now, something that pulls
itself better through mountains while still obtaining similar or even
a little better fuel economy and maintaining driveability seems more
the ticket.  Back to the 5-cylinder in my thinking.