Bad Luck!

So there I was having nearly finished my 88' 4.0L intake/exhaust manifold gasket replacement (what a pain in the butt!) and I was tightening the second to the last bolt in the sequence, actually it's a nut on a stud, yeah the one in the very back- right up against the firewall and behind the exhaust pipe.... AND THE NUT SHEARED THE STUD OFF IN THE HEAD!@!@@$%%$r$ I didn't even get near the torque spec, really! so if anyone has any GENIUS IDEAS of how to drill and tap or helicoil or jb weld that stupid last stud without removing the head or pulling the entire motor then I would be grateful. this is one of those rediculous teeny things that could be the catalyst for a complete rebuild if I am not careful, so PLEASE help me with some realistic ideas- Thanks

Well I have not ever worked this area of the engine but I have worked aircraft and know that a compact 90 degree angle drill is is essential, if I were you I would check with tool rental companies (or buy one). Weigh the cost of rental with the cost of a shop doing the repair.... oh by the way the drill you want to rent/buy needs to have the screw in drill bits, these are way more compact then the chuck type. Once the hole is drilled you can try an Ez-out or like you were thinking tap/helicoil. Good luck!!