FOC for arrows helps with accuracy and penetration. Read the ashby reports on arrows. It helps.
http://www.tradgang.com/ashby/

There is really quite a range of head hweight available for wood arrows. But the more weight you have, the more spine you need. I have 300gr up front on a dozen arrows for my 70# ELB. They spine 100-105. 31" long and average 830gr total weight.  30" draw. Sounds extreme, but they are only 16% FOC.

Here's one that is directed at arrow FOC.
http://www.alaskabowhunting.com/PR/Ashby_EFOC.pdf