If they are stock replacements... just follow your nose. (Cant think why you be replacing the stockers unless something got broken)
I'm assuming your talking about adjustable cam gears. The link below is hands down the best video based explanation of setting up cams and adjustable gears I have come across.
click
If you follow it up with Cylinder Head 206 you'll know more than most people who put cam gears on there cars.
Unless your changing your cams from stock and getting serious about squeezing every last drop of power out of your camshafts/valvetrain, its pretty much pointles changing the cam gears.