There is a major issue in putting "high performance" VW watercooled engines 
in Vanagons, etc....and that is the rpms and torque production.

HP doesn't really mean squat for a van....what is necessesary is to produce 
the torque down on the low end...as opposed to the high end necessary for a 
"pocket rocket" to cruise down the autobahn.

For example, the 5 cyl gas engine in the Eurovan is an Audi unit, which in 
the Audi 5000 puts out something like 125 hp....the EV unit is "detuned" to 
105 hp...but its torque band kicks in at about 2000 rpm and stays pretty 
flat....

The 2.0L 4 cylinder gas unit found in the EV is the same 4 cyl 2.0l unit 
found in the golf...but the EV delivers about 30% more torque at a low RPM 
than the version of the golf which produces about 25% more hp, and its 
torque is at a high end..

I guess what I am getting at is that the parameters that a Transporter 
operates (lower speed, high weight carrying ability) are different from, say 
a GTI or Corrado (high speed, low weight carrying ability), therefore the 
engine requirements are different. You will be sorely disapointed in putting 
a G60 or even a 16v engine in a Vanagon...it will not have any "off the 
line" power...and then at the upper end, the HP will be useless because the 
frontal area of the van will prevent the same high speeds that the engine 
can deliver in the sedan.

Ric