That's an alternate location for the bellcrank. It's got a straight bolt thread, not a tapered pipe thread. Just screw a bolt into it with a little bit of non-hardening sealer on the threads. Some engines had an exhaust manifold shape that required the bell crank to be positioned differently, I believe.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
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