flipscobra Snap-on or Matco make a stud remover socket for your problem. If not,try matco. I think Sears only goes to 1/2" and the studs are 5/8" or 11/16" size. If not you can always lift the head with a small block of wood and remove the stubs with a vicegrip or double nut the tops.
Try not to damage the studs. Some studs have allen head tops, Mine didn't. Other wise it's motor pull time. This may be the best way. This will give you time to check the wholw motor over. How did the head gasket blow??
The L/S should get replaced too, IMO. They where both installed at the same time. This might save another repair or pulling the motor again deal.
Rick L.