Those outter holes are threaded so the bolts just thread right in

But looking at my stock mani I have around here, only the hole on the left (inner left hole) you can see right through into the manifold

and with the one on the inner right, you cant see right through and it kind of goes off to the right, Im assuming attaches somehow to the little hole in the top of the t/b

I just dont get how an IACV work or how I can make mine work with the mani