Re: Acorn nut stuck on stud
Unthread the stud from the case with the acorn nut still on it. Clamp the stud in a vice and carefully unscrew the acorn off the stud. You might want to repair the threads with a die then reinstall the stud, throw the acorn nuts in the trash and pick up some good quality hex nuts, preferably the shouldered type and use those.
I recommend removing the cylinder head and using two hex nuts, back to back (double nut) and torque the studs into the case (120 to 140 inch pounds) then install the cylinder head and new nuts. Torque them to the same value as you did the studs.
Those pretty chrome acorn nuts are probably responsible for more head gasket and compression loss problems that any other factor. Throw them away.
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