Originally Posted by
stevesbike
Best bet is to install your crank and then set the derailleur height relative to the large chainring. Depending on maker, it should go a few mm's above the large chainring.
If you look at Park Tools repair site for the article on adjusting the front derailleur, they use the thickness of a US penny to set the gap between the large chainring teeth and the bottom of the FD cage. That's what I do (with just a bit of slop) and it works perfectly every time.
http://parktool.com/repair/readhowto.asp?id=75