Chevy 350 ???

[uglyjeepoffroad]

I am well on my way to cleaning up all of the vacuum/ exhaust leaks on the 350 in the tow rig, but I have one more question.

The stock air cleaner assembly (which is now residing on the scrap pile) had the little vacuum operated flapper door that helped to warm up the engine. This has 2 thermal vacuum switches in the thermostat housing. I am swapping the intake manifold, so they will go bye-bye too.
My question is about the vacuum canister mounted to the passenger side. It connects to the exhaust manifold and closes it off a little to help the manifold heat up quicker, I think.
When no vacuum is applied, does it close, or stay open? Can I take it off completely, or do I need to block it off?

 

[Ron]

You can remove the entire vac canister.
One word of caution, the exhaust flapper is notorious for burning out or rusting out the spring and becoming hung at 45deg. essentially adding restriction to your exhaust.

I ALWAYS drill/hollow out the pin and remove the entire mechanism.