Adjustable Cam Gear - 2.0l 16V

[rfkellner at snet.net (Rick Kellner)]

I am headed to a swap meet this weekend and will be looking for an
adjustable cam gear for a 16V, 2.0l motor.  I know you can move the HP
curve forward and back with the gear however; what have your experiences
with the gear been and in particular, moving the HP down to lower RPMs?
How well does it work with the 16V?  Does it have any effect on knock,
fuel requirements and etc?
BTW, the motor also will have a 'euro' intake cam.
Thanks, Rick Kellner.