Last time I had low power I had a fuel leak with bad mileage.  I
replaced a 3'' section of fuel line in a Chick-fil-a parking
lot.

The time before, the wonderful Bosch Plat +4 finally gave up
after 65K miles and got crudded up.  I pulled over on the Blue
Ridge Parkway and popped in an old set of plugs until I got
replacements.

You did say that the problem existed with the previous engine,
which MIGHT point to a problem outside Bob's motor.  If you see
above, once my problem was due to lack of fuel, or pressure, the
other because of lack of spark.

So, what's your fuel pressure?  Did we put in new plugs, wires,
cap, button?  Do a compression check to see if your valves are
not shutting all the way.  Check the EZ stuff before you dive
into further complex analysis.

Good luck.

=====
Chris S.

'84 Westy -> http://www.knology.net/~vw/vws/hershey/
'01 NB TDI -> http://www.knology.net/~vw/Beetle.jpg

1-888-VW-PARTS <- Recommended Expert Vanagon Part Source