Where to drill my tank?

[e46er]

I would go at least 2" to the top of the hole from the trim. On my own tank I'd probably go 6" to center for piece of mind.

[daplatapus]

If I remember correctly, the correct measure is 1 1/2x the hole diameter from the edge and 2x the hole diameter from another hole.

[Easto]

If it were your tank how long would you place the holes? I need to take into account the elbows for the drains for the BA overflow.

[daplatapus]

Are you thinking of doing an internal or external overflow?

[Easto]

Internal