Where to drill my tank?

[Easto]

I have 1" bulk heads, 75 Gal tank with black trim.

In relation to the black trim at the top, how far down should I be drilling my holes?

1 suggestion I have heard is the middle of the hole 3" below the trim. Anyone else agree/disagree?

I don't have an overflow box as of yet.

I'll be plumbing a Bean Animal.