Battery cables -where does the negative go?

Okay folks- I went to my 66 Barracuda “s”
Parts car for the correct bolt to mount it to the head... there’s no bolt, not even drilled for a bolt. It’s under the spring return for the carb. I can bolt it to the new engine for my car to that point but something it telling me that’s not correct factory point for a formula S car. No offense but my parts car is all original. Never been apart. Engine is actually red not orange in photo- cheap camera. FE4766C7-C1EA-4A40-AAD1-842D92666648.jpeg
Joe

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