Zinc Additive for Flat Tappet break-in?

Hughes has an "extreme pressure oil additive" that they sell too, supposedly designed specifically for flat tappet cams.....and they also sell quarts of oil that is already mixed with the stuff...but it is a bit pricey!
http://www.hughesengines.com/partDetail.asp?partID=12866&eTypeID=20

http://www.hughesengines.com/partDetail.asp?partID=12883&eTypeID=20