if you have a head 'fire ring' blown, remove the intake and exhaust and that head only. Have the head checkd for warpage and install new fire ring. If the head is not too badly deformed, we use another sleeve, new fire ring secured to it with gasket glue and install head with valve grinding compound between the head and ring and 'lap' the surface of the head to the new ring. This is done out side the engine. This will seat the head to the fire ring. Then final lap the head to the real cylinder jug top as best as can be done since the head can not be turned very much in the engine. Clean. Retorque to specs - 30 foot n's then 45 degrees three times then 30 degrees final. We add another 5 degrees usually. IF the head bolts seem not exactly right , use new ones. IF the old ones will not come out - we work on some fertilizer plant loaders that use deutz units and they are real bears, we heat the block just around the bolt to 300 degrees or so, cool the bolt w_ water and use a rounded u shaped chisel in an air chisel at the base of the bolt to vibrate it as a turned down inpact is used on the head bolt to loosen it. MAy take a while but is 99% successful. Just dont twist off the head bolts. Drilling and tapping aint fun.
