I am about to finish the cylinder head job, everything went well, until troqueing the head nuts to the last step to 36 ft lb. The number 4 nut on the lower middle was a little soft and difficult to get to the right tension. I adjusted all nuts to the right torque then went back to tighten the last #4 nut. I do not know how but it did happen, the nut and about an inch of the stud broke off from the head. I have spent three weekend on the job, and do not know what to do next....
The first question is, can I block the stud tunnel with some sort of liquid steel and run the engine with 7 nuts to secure the head?
The second question is how do I fix the broken stud? Do I have to take to whole engine off?
Any suggestion will be greatly appreciated. Thanks

Leo, 1991 Westy Multivan, 110,000mls