I remember there was lots of discussion included with the stencil whether it's 3" from the hood's edge or 2". "They" said the correct placement is 2" from the molding's seam which on my car makes it 3 1/4" inches from the outer edge of the hoods lip. You can see that on the photo I previosly attached. I went with their instructions, right or wrong.
I noted Don sent you some measurements to your PM, I'd go with them if I were you, Don knows these cars much better than most and I'm betting what he sent you is correct.