Breather Cap Question

[Moose Drool]

I have an '84 K1500 with a crate 350 that the PO put in. It has breather caps on both valve covers that need new ones. Do they both need a breather?

There is no state emissions testing needed.

I included pics for detail.

You must be registered for see images attach

You must be registered for see images attach

 

[Silverback85]

I’ve always heard they need to cross vent like yours is set up now but I’m not sure don’t take my word for it I know not having a vent cost me an intake gasket once

 

[Turbo4whl]

Should have a breather on one cover, and a PCV valve on the other cover. Can't see in your picture if there is a PCV, but if there is, that valve cover does not need the breather. Also with a breather on the cover with the PCV, then it will not be pulling the crankcase fumes very well.

 

[Rusty Nail]

See here in this pic?

That port in that carburetor should have a PCV valve at the other end. Your truck will run much better soon.
Put in whichever part# is correct for the application (84 k1500)
Good luck!

You must be registered for see images attach

 

[Moose Drool]

See here in this pic?

That port in that carburetor should have a PCV valve at the other end. Your truck will run much better soon.
Put in whichever part# is correct for the application (84 k1500)
Good luck!

You must be registered for see images attach

The port with the hose attached? It leads to this?

You must be registered for see images attach

 

[Moose Drool]

Should have a breather on one cover, and a PCV valve on the other cover. Can't see in your picture if there is a PCV, but if there is, that valve cover does not need the breather. Also with a breather on the cover with the PCV, then it will not be pulling the crankcase fumes very well.

No PCV anywhere that I can see.

 

[Turbo4whl]

The PCV would be a larger port (3/8") on the base of the carb. The smaller port in the third picture is the vacuum advance on the distributor.

Most likely the PO used that large port for the brake booster vacuum. In your application the brake booster probably should be plumbed to a pipe fitting on one of the intake manifold rear runners. (there also could be a pipe plug available on the base of the carb for the brake booster)

 

[Moose Drool]

The PCV would be a larger port (3/8") on the base of the carb. The smaller port in the third picture is the vacuum advance on the distributor.

Most likely the PO used that large port for the brake booster vacuum. In your application the brake booster probably should be plumbed to a pipe fitting on one of the intake manifold rear runners. (there also could be a pipe plug available on the base of the carb for the brake booster)

Could it be this port?

You must be registered for see images attach

 

[PrairieDrifter]

Could it be this port?

You must be registered for see images attach

Yes the big one in the center.

 

[Moose Drool]

Thanks everyone for being such a great help!

I will go down and get a PCV, some hose and a new breather.

One more thing..... Do I need to run anything from the Manifold Vacuum Port?

 

[Curt]

Some then like that

You must be registered for see images attach

 

[Rusty Nail]

Thanks everyone for being such a great help!

I will go down and get a PCV, some hose and a new breather.

One more thing..... Do I need to run anything from the Manifold Vacuum Port?

Be more specific pliz.

 

[Moose Drool]

Be more specific pliz.

Is there anything that I should hook up to the remaining port to the right?

 

[75gmck25]

The vacuum advance can run off either manifold or ported vacuum on the carburetor and the original emissions setup was probably ported. However, I like manifold vacuum because of the additional timing advance I get at idle.

Do a google search for ported vs. manifold vacuum and see how many discussions you find. It’s like a religious issue, lots of talk but no firm consensus.

Bruce

 

[Curt]

I don’t think so....not with your current set up.