I doubt that the jb weld will work.With my past experience with cobbing stuff with jb weld it has only worked on pluging holes and not fixing cracks that are caused by some kind of stress on the broken part
My tranny cracked in the same place. Tried JB weld, it didn't work. Too much stress for the jb weld. Used rtv silicone to keep the leaking down but it has now cracked all the way around. Time to replace it.