I had to remove the head because the exhaust manifold stud nearest the firewall was broken off about 2mm below the head surface. I tried drilling the stud and using a screw extractor, but the drill went off to the side and part of the hole was drilled into the aluminum head.
In retrospect, I should have tried tig or mig welding a nut to the stud remnant. Another method would be to use a bushing to keep the drill concentric. If you need to remove the head, new bolts and a head gasket kit will set you back about $400.
Everything is back together and "Old Smokey" is back on the road. I must be getting old because I still like the way this car drives, especially on the interstate. I was driving my BMW 535i with a five speed while the 350 SD was in dry dock.