Alright so I am trying to install a Weber on my 75 pickup. I have no idea where I’m supposed to connect the pcv valve. In the stock carb it connected to the bottom of the carb, which is not an option with the weber. Where am I supposed to connect the pcv valve? I can post pics if needed.

 

Any manifold vacuum port will work. Later engines had a connection port on the intake manifold (see picture). Your manifold lacks that connection (from what I can see).

If you’re not reinstalling any pollution controls back on the engine, I would remove that outermost threaded vacuum nipple(large size) and replace with a nipple that will accept your PCV hose.

 

After doing a lot of digging around I saw that someone put it here (where my finger is pointing). Should that be an alright spot?

 

I think that’s just an unused attachment hole. Most vacuum ports have some type of fitting on them. See if a small drill bit will push all the way through. Next blow some compressed air into the hole and see of you hear it at the carburetor flange. The hole diameter itself is small for a PVC hookup.

Personally, I’d remove the large threaded fitting on the outside edge of the manifold and use that for your hookup.

FYI those 2 piece adapters are notorious for vacuum leaks. I disassembled mine and used aircraft gasket sealer on both sides of that center gasket. You’ll be glad you did.

 

This is before I took the vacuum connector out. So you think a bigger port would be better? Also yes I heard about these adapters failing was just scared to use sealant on it because fuel and didn’t know what to go with due to mixed reviews. Don’t want to get the brand new carb clogged up. So that aviation sealant worked good for you? When these gaskets fail I’ll probably switch to what you’re suggesting if you have luck with that.

 

I would use the larger port. You could drill a hole in the face, then tap a threaded hole for the proper size barbed hose fitting.
If the hole you pointed out is in fact a manifold vacuum source, you could drill, tap, and install the correct hose barb for your PCV hose I.D.

 

Are you talking about the one on the very left of the picture (brass two ports) or the one with the white end that the distributor used to connect to?

 

Far left is a vacuum port. You could reuse that fitting by drilling and tapping a hose barb fitting on the face, then capping the two small fittings.
Your distributor works on ported vacuum. Any fitting below the carburetor are manifold vacuum.
Your engine is older than mine so there may be some difference. Distributor advance is controlled above the primary butterfly’s.

 

kay thank you!! I’m glad to know this now. I’m a newbie to carbs this is my first carbureted vehicle. I’m going to have to cut the barbs off to be able to get a socket over it becauseit will not come off! So I’ll have to buy a new fitting

 

You could leave in place and drill for new barb. Also, check those other openings, maybe one is a manifold vacuum port.

 

I ended up cutting the barbs and got it off with a socket. Bought a 1/2in-3/8 barb fitting and ran the pcv there. Thanks for the help! I just got the head rebuilt so I was eager to get this thing running and boy am I happy with the Weber!

 

You were darn right about the adapter plates. Can’t keep the thing idling because of the leak.