Daniel,

<< I have found it now problem to keep up with normal traffic,
and the only time the wbx could use more power is in climbing grades at
highway
speeds. But it's the van's brick-like aerodynamics that are the problem, not
this
engine.>>

Actually the engine is the problem (along with the aerodynamics), it simply
does not put out quite enough power to move the 4000 LB (Mine is at least)
Vanagon quickly.  I chose to add a few proven T1 parts and modify a few
internal engine parts to increase my power.  The changes increase the life of
the engine not decrease because the engine runs more efficiently.

I can keep up with traffic easy, often I lead... On the highway I can
maintain and increase speeds going up hills.  I can be going 70 mph, press
the gas and in a few seconds hit 80 mph (testing power, I drop back to@ 75 do
not need a ticket)
The range of my engine is from @1500 RPMs to @5000 RPMs (I do not need to go
higher)

<<For smoothness, quietness and overall driveability, I don't think you can
beat
the stock 2.1L engine. I wouldn't consider putting something else in back
unless
I had a real need for a lot more power. Gas mileage could be better, but the
cost
of a conversion will buy an awful lot of gas!>>

On my last trip, I was getting @23 at 75 with occasional bursts to 80 mph,  I
had also lowered my front tire pressure to 30 psi down from 40 psi to check
the ride effects.

Robert