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To start, I have a '78 Black Pearl, (Real638), which I've owned since early '81. The car has not been driven since around 1990, & I just started working on bringing it back to life a couple of months ago. The engine had never been apart - it made it 184K & still ran ok when parked. It is missing the rear lifting lug & for all I know it may have been gone when I bought the car. I know the issue of broken rear exhaust manifold studs has been covered several time before, but I'm not satisfied with the explanations I've seen for this & I can't find an answer on how to solve the problem. From what I've read the hook is gone & the stud broken on nearly all 1st generation Zs. Banzai Motorworks says they reproduced the early lug because nearly all the cars that came into their shop were missing it. When I pulled the manifolds I found the stud had broken flush with the head. I broke 2 others during removal, as well as the bolt in the front, and one bolt for the radiator hose fitting on the other side, but they all broke with about 1/2" showing. These came out easily with a little heat & vise grips. Yesterday I looked at a '78 in a wrecking yard. Rear stud broken flush with the head. Same with a '74 & early 240 in the same yard. I did find a '77 with the stud, nut & lug still on it! When I put a wrench on it the nut & part of the stud literally fell off - broken flush with the head. I've seen a couple of theories to explain this. One is warping of the manifold causing the stud to break. The other is over tightening during repairs. Neither of these theories, while possible, satisfy me. I think Nissan used the lugs during assembly & that little 5mm stud bent, at the head, & cracked. I'm thinking about making up a sleeve, with room for manifold heat expansion. Thoughts on this?