apparently one of my exhaust manifold stud came loose and broke the thread off on the head.. i tried using hi temp thread locktite to thread the stud onto whats left of the thread on the head...it doesn't seem to work.. so i thought about rethreading it and helicoil it.. the problem is the thread hole for the exhaust manifold stud is very very shallow.. i can't not even get a rethreading tool in there to get started.. i was thinking that the stud would have gone deeper into the head..the hole depth seem to be only a 1/4 of an inch..... how would i go about threading this? any help be great

 

Let me see if I have this right...

The stud stripped the the threads out of the head right? And you're saying that the hole for the stud is only 1/4" in depth making it difficult to repair?

If I have that right...Yes it is a ***** to drill out the hole and tap and heli-coil because you cant EASILY get a drill in there. Are the threads completely gone in the head?