Re: Cylinder Stud broken
Yup... it's either seized up or red locktite was used at some point. Heat will get it out either way. Like Tom said, just apply heat on the side of the case where the stud is seized, keep the vise grips locked on the stud really good, then just hold some steady pressure on the vise grips as the aluminum is heated, once it gives and starts to turn you can take the heat off and get it out, no need to keep the heat on after it starts to move unless it locks up again on its way out.
During assembly a Thin coat of anti seize on the threads will prevent this from happening again, set the new stud, and torque the nut as usual. You can use regular he nuts instead of the problematic acorn nuts, ditch the split lock washers and use the star washers on top of a flat washer and it should stay put after assembly, but will most likely need re torqued a few times after the engine has run thru several heat cycles.