Vacuum Switch on 454

[79Sea30]

Afternoon All-

Hoping one of you may have some experience to help with my current question. I'm in the process of swapping intake manifolds on my 79. Truck is a 454, 4speed, with AC. The AC is fully removed and I do not plan to reinstall. While swapping the manifold to a Weiand Street Warrior, I noticed the vacuum switch in the front of the stock manifold had cracked connections. When I went to remove and reinstall on the new manifold, it fell apart in my hands. I ordered a new one, and have that at home, but now i'm curious? Do I need it? Truck is a carb 454, manual transmission, and stock outside of the edelbrock carb, and headers. Just wondering if it's necessary, or If I can just block it off on the new manifold? I looked up other threads, but nothing that specifically answers that question. Hoping someone can help.
Cheers,

Kyle

 

[Radiohead]

If your rig doesn't need to meet emissions equipment requirements upon licensing, you can ignore the device and roam about the planet at will. I believe that sensor allowed vacuum to do its thing after the coolant got to a particular temperature.

 

[Bextreme04]

Exactly what radiohead said. Depending on year and what you have installed, those thermal vacuum switches are used to keep various emissions things from functioning until the vehicle warms up, such as vacuum advance and various heat riser things on the exhaust and air cleaner. If you have removed all of that, then you don't need any of it.

Pics would help us give you a definitive yes or no.

 

[Turbo4whl]

@Radiohead was kind enough to post his emissions sticker, but for Cali, not 49 state.

You must be registered for see images attach

His shows 2 TVS (thermal vacuum switch) sensors for 1979. Between them both they control the EGR, the hot air stove, the charcoal canister purge and the trapped vacuum spark. The hot air stove and trapped vacuum spark help the engine when cold.

If you have removed them all except the charcoal cans, then yes you don't need them. Hook the charcoal can purge to ported vacuum.

 

[79Sea30]

Thanks for all the quick replies. Vacuum lines are currently setup as. Distributor to a tee. One goes to carb. Then the other goes to a split vacuum hose running to the vacuum switch in the front of manifold. There’s also a 90 deg port that runs from manifold to canister above hvac on the passenger side firewall.