Cold Fusion is the way it would get welded at my shop as well. For something like that, be sure the head surface is ground flat again (have the entire head surface milled flat) before you try to bolt it up, or it will break again. If you get it welded and it breaks again, get a new manifold. Cast iron that has been through several heating cycles sometimes won't weld good regardless of the method used.

The JB Weld fix lasted bout as long as I expected. It simply doesn't work anyplace there is a tension. Gene