Pulled the head off the JD B to replace the manifold. Used a high speed cutter to cut off what used to be nuts and removed the manifold. I heated the head around what was left of the studs and melted wax around them. Vise grip was useless, but at the bottom of the tool box was my ity bity pipe wrench (it's about 5 inches long). I put that on the first stud and tapped it with a small hammer and it broke loose as did the second and third one. I was proud of myself and maybe a little cocky when I got to the last one and went at it with a bit more vigor, bad words were said after it broke off a little below the surface of the head. Now what?