Probably won't make much difference. Total foot length is about 8 inches, but about half of that is routed out in tapers for the foot and point taper. You're left with the weight equivalent of about 4 inches of hardwood, which you are using to replace the equivalent of 4 inches of cedar. I presented these figures in another thread, but I'll repeat them here. A modestly heavy cedar will weigh about 12-14 grains per inch, a hardwood, about 20 grains per inch. Thus, you're only adding about 25-30 grains to the front of the shaft by footing it, maybe a little more if you have lighter cedar and/or heavier footings. That's not enough to require a change in spine. And, in my experience, footing the shafts doesn't change their static spine either,mayube a pound or two. So foot away, and when done build the arrows just like you've always done.