here's some math help, for reference since the sight has been ordered:
http://www.baitshopboyz.com/forum/forum_posts.asp?TID=9173&PN=1

when i put the williams peep on my 336 cs, i needed roughly .400" of front sight height.

since i have heard mixed reviews of the firesight, i went w/ a .410" marbles version of the firesight. works well.

Hunting is not a matter of life or death. It is much more important than that.