You will know soon enough what studs you need to provide force on when it starts to lift!! You are very wise to drill and tap for that stud, once you have started you will not want to stop, remove everything and drill and tap for a further stud!!
How will you attach the plate to the head? This is the one variable. I would favour straps to the manifold studs, but if you can come up with an easier way that would be excellent!
Good luck, Andy