8lbs of LME, that'll be a hell of a beer
. There's a few good posts around on spruce beer, and I found this one helpful http://www.homebrewtalk.com/f12/spruce-tips-popping-do-i-dare-60942/
I made the basic spruce beer from "The Complete Joy of Homebrewing" over the winter, and couldn't get ahold of spruce tips so I used spruce extract from my lhbs. If your beer isn't sprucy enough, spruce extract might be an option but add to taste by very small amounts. The blue spruce in my yard just started to grow some tips, so I think I'll brew this again using real spruce tips now...