There's a plug there, that's how the valve actuates.

On a side note: UPDATE!
I finally got time to work on the truck. The intake manifold gaskets on the original intake were LEAKING BAD! Also, I could not believe how much oil was present in the intake manifold and intake ports, so much so that it was leaking past the intake gaskets and had accumulated a severe case of crud around the manifold ports. I NEED a catch can/PCV re-route baaaad. Tore it apart yesterday, cleaned up the stock manifold and injectors, and used my new gasket set to re-install the stock manifold so I could optimize my tune AS-Is and get some baseline numbers. Here's a reminder to all that remove and replace their manifolds, check to ensure you MAP sensor gets plugged back in, otherwise you'll have transmission shifting issues, TC lockup issues, starting fumbling, engine load issues.......... you'll just have issues, OK? Don't ask me how I know, but I felt like a dumbass today at lunch when I finally realized why my drive in this morning wasn't as "Nice" as I had hoped. Luckily I brought the Flashscan V2 with me and found the issue after I checked the DTC's.

Once I have the tune nailed down, I'll swap the intake out and post some results.

I have to say, the truck is a whole different animal now that I don't have a vacuum leak from hell. The brake pedal is substantially more firm, the accelerator pedal is quite a bit more responsive, and I HOPE I'll see increased fuel mileage. Then the TBSS manifold and 90MM Edelbrock TB go on!

Now I just need to wire in that LC-1.........