Ok, just a safety-check before I wreck something...
Please draw on the attached image where you mean to avoid misstakes.
I'm about to fit alignment pins (2mm) to align my knock-off manifolds with the head and the gaskets, 2 per manifold will do the job. Will need to drill approximately 5mm in to the head, where will it be thick enough so I don't hit an oil or water alley?