Reply by ChuckV

These are great suggestions. I would highly recommend that you test things out on some scrap pieces if possible. If I understand, you are attaching two pieces with the grain directions perpendicular and are nailing into the 3/4” edge of the selves. So it is not possible to make both boards happy with the orientation of the nails. You might have to experiment with various pilot hole sizes to find the combination that will prevent splitting and still give a solid connection.

-- I was walking down the street, something caught my eye, and dragged it 15 feet.