Ported or manifold vac for overdrive bypass vac switch?

I have a vacuum kickdown solenoid installed on a 360la a500 overdrive combo, (got the car set up that way) and I'm wondering which vac port to run it to.

Here's the solenoid
IMG_20240819_091358391.jpg
IMG_20240819_091340772.jpg

The idea behind this (I'm told) is that during normal driving, it would go 1, 2, OD. But with this hooked up properly, when you floor it; it should go 1, 2, 3.