Gravy Waves

I currently have a '61 dynamic 88 and I just slapped a 4-bbl intake on it (2-bbl originally). Only until after I had sealed it to my cylinder heads did I realize that the old water neck was too small for the new manifold. Would anyone know of a place that sells a water neck that would fit this new manifold? I'm just looking to get it running at the moment, pretty can wait. The distance between the two bold holes is about 10cm, or just under 4 inches. I've looked all over but no one lists the distance between the bolt holes.