Ram horn headers hidden lever?

[C101971]

I was about to clean my block in prep for painting, and as I was about to unbolt the passenger manifold (stock ram horns) I noticed a lever of sorts that appears to be attached to the manifold. I'm not sure what this does, it is the first time in my life I have ever seen a manifold with this little guy on here, and I've been around sbc's all my life.

Anyway, it was there and appeared to be held at a certain point in via tie wire around the lever and exhaust pipe. Can anyone tell me what this does exactly? And why it was being held in a certain position?

I doubt it would be some kind of exhaust cutoff or anything like that. It is only on the passenger manifold, not the driver side