i don't have the exact numbers as i forgot where i wrote them down at (i think i did post them in the mechanics forum if you want to search), but i saved around 26oz. by converting to threadless. swapped the columbus steel fork, orginal campy threaded headset, original itm bars and itm stem out of my mid 80's bianchi with a bianchi carbon fork, aheadset, itm aluminum stem and itm carbon bars.

this was enough weight to make the bike feel considerably lighter, it also rides much better, much smoother. i think good steel is awsome in a frame, but a carbon fork provides a much better ride.