Technical Breather valve...

I installed a little "bling" on the T Bird today and the valve covers came equipped with an oil fill plug, and a breather valve that I connected to the air cleaner. The old girl has a little bit of "blow-by" and was wondering, with the new accouterments, couldn't I plug the old oil fill breather cap, and just run the fumes back through the carb? It's pretty noxious when you first start it up... I have included a pic showing the valve cover breather valve and the oil fill breather.

 

That looks like a PCV valve, should be plumbed to manifold vacuum.

 

What @saltflats said. It looks like the right cover should have a PCV plumbed to the intake vacuum and the left cover gets a breather or route it to the air cleaner.

 

To do this right will require some more work/parts...

You've got the 'old style' crankcase venting with venting at the oil fill and a 'road draft' tube at the center rear of the intake. In '65 Ford switched to the valve cover venting/oil fill and deleted the manifold fill and road draft, which is what your new covers are designed to reproduce. This was done to reduce sludge build-up in the top end. You'll need the right carb spacer with the PCV hose connection (not so easy to find anymore, particularly with the heater hose 'pre-heat' connections and/or for the 4-barrel carb) and the new oil fill cap needs to be vented into the air cleaner (although some pre-'68 systems vented to atmosphere). Then you can block off the oil fill AND the road draft tube.

You DON'T want to connect the PCV directly to the intake as that will lean out 1/2 the cylinders and make tuning impossible. The factory spacer draws vacuum from all cylinders, allowing proper tuning. What I've done for a spacer if you can't find a OEM one is use a 1" plastic spacer from Summit Racing like this... Summit Racing SUM-G1412 Summit Racing® Carburetor Spacers | Summit Racing ... and drill/tap it for a 3/8" pipe thread and install a hose ****** for the PCV hose. These spacers are hollow inside, don't use a 'open' spacer, you need the 4-hole type. Do be careful doing this, it's easy to tap too deep and don't get carried away when tightening it, these are plastic. With the hose connection pointing to the rear, then cut two small 'notches' into the front carb bores into the hollow part, this will supply adequate vacuum for the PCV valve. I've attached a pic of a 2-barrel spacer to give you an idea of how it should look.



You will lose the heater hose 'pre-heat' (not a big deal where you live) so you'll have to re-do your heater hoses.

 

Thanks for the info. This is the reason I am a member of this great forum!