When I set up my little foundry last summer I built these 2 pouring shanks.The first one is made from an oversized set of fireplace tongs that I had picked up cheap for this purpose. It is designed to hold a #8 clay graphite crucible just snug not tight. the cross piece on the pouring lip was welded on as an after thought to assist in skimming the crud in an iron melt.
The second shank is for pouring a 5 lb capacity steel crucible for aluminum melts.
In use for a good number of melts now, they have both performed very well.
Seems to be some interest in casting here I will upload my molding bench and some casting photos in a later thread.