Engine Wiring

[Beall57]

Been a on the forum for a while this is my actual first post! Little info I have a 1984 K30 SRW with a SB 350, turbo 400 trans and a 205 transfer case. Dana 60 up front and 14 bolt upfront. The original motor crapped out so I am in the process of putting in a crate 350 in it. Which leads me to my question the original manifold had some vacuum lines connected to it to a thing called a Speed switch valve. What is that and what does it do? That valve sent 2 wires to what the wiring schematics are calling Speed SW which I am assuming is switch? What is this and how can I remove it because I am putting Hooker headers on it and there is no option for this setup and I would rather not have random wires in my engine bay. I am attaching photos of the setup thank you so much for the info.