I herd someone talking about it on early Carb sixes... does it change the torque curve? move horse power to different rpm? what exactly would be the reason or advantage to doing this?

Just wondering,
Mike D.

Advancing the cam timing typically shifts the hp and torque peaks lower. Conversely retarding the cam timing shifts the hp and torque peaks higher up the RPMs

The shape of the particular cams curve remains the same.

YOu can take a peaky S cam and advance it so you get into the power a bit sooner, but if you advance the cam it also wont scream to 7800 with authority anymore.

Unless you have the luxury of a dyno to actually see what happens when changing the cam timing specs.. keep it to stock specs.