5.0 intake vac lines

Nov 23, 2019
26
6
13
Ohio
Good morning. My son and I picked up an SN95 for like 1k last week. Perfect for us as we are building a 347. We got the car and started to take the motor out and the upper intake was just laying in there. My question is regarding the vacuum lines. There are 3 ports, and we had broken hoses laying around the intake. I have pics, can someone tell me where these lines run from into the 3 ports? Thanks
 

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Good price on an SN.

So yeah, to the best of my recollection, having not had a stock intake on my car in almost 20 years, I'll try and recall the vacuum puzzle. The section of hose that you have sticking off the back of the intake goes to a T splice that connects to that screw in vacuum port on the far end of the intake that you have in the first picture, then goes to the PCV valve that is on the second picture. That PCV valve plugs into the back of the lower intake near the bottom. Just look at the very back near the transmission bellhousing at the center of the intake, and there is a hole there for it to plug into. The other vacuum port on the bottom of the intake is the main vacuum line that goes to the vacuum tree which is mounted to the inner fender right by the brake master cylinder. That supplys vacuum for stuff like the brakes, the HVAC, cruise control, etc.

Kurt
 
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Good price on an SN.

So yeah, to the best of my recollection, having not had a stock intake on my car in almost 20 years, I'll try and recall the vacuum puzzle. The section of hose that you have sticking off the back of the intake goes to a T splice that connects to that screw in vacuum port on the far end of the intake that you have in the first picture, then goes to the PCV valve that is on the second picture. That PCV valve plugs into the back of the lower intake near the bottom. Just look at the very back near the transmission bellhousing at the center of the intake, and there is a hole there for it to plug into. The other vacuum port on the bottom of the intake is the main vacuum line that goes to the vacuum tree which is mounted to the inner fender right by the brake master cylinder. That supplys vacuum for stuff like the brakes, the HVAC, cruise control, etc.

Kurt
Thank you Kurt. So just to recap:

the 90 degree fitting goes to the vacuum tree
The other port in the first pic goes to a “T” and then to the PCV valve? What goes on the other side of the “T”?
It looks like the really small line in the first pic goes to the fuel vapor return?
We are actually in the garage working as we speak.
 
Ok, so not quite. In the first picture, there is one nipple on the bottom of the intake that has almost no hose on it. That one goes to the vacuum tree attached to the fender. The other vacuum nipple on the bottom of the intake has quite a bit of hose still on it. That hose goes to a T at the back of the intake where that giant screw in piece is, and then continues on to the PCV valve. So it gets vacuum from both the bottom of the intake, and the back of the collection portion of the manifold to suck from the PCV valve. No clue why it's like that. I wouldn't put too much effort into it honestly. Make sure there is vacuum going to the tree, and vacuum going to the PCV valve. If you need to cap a nipple, just go ahead and do it. You are going to need an aftermarket manifold for your 347, and it won't be setup like that, so don't over think it. Obviously you will need new hoses. Just get bulk 3/8" fuel hose from the parts store for 78cents/ft or whatever. It will work fine.

Kurt
 
Ok, so not quite. In the first picture, there is one nipple on the bottom of the intake that has almost no hose on it. That one goes to the vacuum tree attached to the fender. The other vacuum nipple on the bottom of the intake has quite a bit of hose still on it. That hose goes to a T at the back of the intake where that giant screw in piece is, and then continues on to the PCV valve. So it gets vacuum from both the bottom of the intake, and the back of the collection portion of the manifold to suck from the PCV valve. No clue why it's like that. I wouldn't put too much effort into it honestly. Make sure there is vacuum going to the tree, and vacuum going to the PCV valve. If you need to cap a nipple, just go ahead and do it. You are going to need an aftermarket manifold for your 347, and it won't be setup like that, so don't over think it. Obviously you will need new hoses. Just get bulk 3/8" fuel hose from the parts store for 78cents/ft or whatever. It will work fine.

Kurt
Now I see. Smaller diameter goes to the tree, the one with the hose goes to a “T” over to the large 90 degree fitting over to the PCV valve.
You are correct, my trick flow intake is setup a little different.
Thanks for replying to my post.
Happy Thanksgiving.
 
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The one on the bottom of the intake goes to the PCV and the one on the top with the 90 degree elbow goes to the vacuum tree.

I've eliminated my vacuum tree after removing all the EGR / Smog equipment. I use the top of the intake for the booster now.