Leaderboard

Picking up a new head won't be a cheap option. He has a turbo car and those heads trade at a premium and then you would have to make sure all the hydraulic adjusters are good. I would remove the intake and exhaust, if there is enough to grab acetone/ ATF for a couple of days, hit the end with a hammer and try to vise grip it out. If it wont come out, remove the head and drill it out or take it to a machine shop for removal.

The failure of the rearmost manifold stud seems to be common to the Z L-Series engines and it's the bane of a lot of Z owners (i.e. welcome to the club). Your ex-Nissan friend's statement that the cause comes from rearward shift of the manifold is interesting -- many have speculated on why this particular stud shears off, but I'm not sure I've ever heard exactly that explanation before. In the end, though, 'why' doesn't really matter. You need a solution. Because I have to deal my the same problem with my '70 (and I'm about the same age as you), let me think out loud for both of us: Note: Everything I say below is premised on the assumption that the stud is sheared off flush with the surface of the head, so that there's nothing left to grip on. Solution #1: Remove the stud using heat and an EZ-out. As noted by Patcon, the intake and exhaust manifolds are going to need to come off. Then you'll need to drill an accurately-centered/directed hole into a small-dia stud and use the smallest-dia ez-out in your toolbox. From my experience, this is a certain recipe for disaster. It's going to be hard to get that hole drilled accurately with the engine/cyl head still in the car. I predict the end result will be an ez-out snapped off inside the stud. Now what do you do? Solution #2: Forget about trying to drill a hyper-accurate hole and forget about using an ez-out, too. Forget about trying to save the old threads. Just drill a reasonably accurate hole into the stud, then keep stepping up the drill bit diameter until you've taken out all the stud material and created a hole in the aluminum head casting suitable for tapping for a next-oversize stud. I believe this is the most common solution, historically. You may want to wait to hear what others have to say about this, though. Solution #3: Remove the head and take it to a competent machine shop. There's an element of trust involved in this approach. You may end up with an oversize stud anyway (see #1, above). Solution #3: Remove the head and try the ez-out strategy, taking advantage of better access to drill an accurate hole and apply directed heat. Good luck with this. I've recently tried to get a snapped-off mounting stud out of a Honda windshield wiper motor casting. The stud has a 6mm thread. The motor/casting was sitting on my bench in a vise, so I had perfect access. I pre-soaked the stud with repeated applications of acetone/ATF for over a week. I applied heat repeatedly for over two minutes. I even tried cold-shock, using an aerosol spray-cold fluid. Result: On my sixth cautious attempt to get the stud to move, my name-brand ez-out snapped off inside the stud. I might have had a better result using an oxy-acetylene torch for heat, but I don't have one (and it probably would have fried the wiper motor wiring anyway). Solution #4: Remove the head and take it to shop that offers 'metal disintegration' services (also known as 'electrical discharge machining' or 'spark erosion'). Good news: You'll get to keep the original threads and stud size. Bad news: According to others, It's going to cost you $200 - $300. Can anyone else confirm? Solution #5: Remove the head and replace it with a used one. Z cylinder heads seem to be dirt-cheap. Of course, you'll need to be sure that the one you get is straight and not damaged (check the cam lobes for good wear patterns). It may need new valve seals (but then, the one on your engine may already need these anyway).BTW, all of the head-removal strategies are going to require ponying up for the cost of a gasket kit. Comments, anyone?

For those of you (myself included) that don't like the 280z 5 mph bumpers...