The picture you show is correct. The line comming off the brake booster at the white fitting goes to the back of the carb. The white fitting is a check valve that allows vacumn from the engine, to assist the brakes. Thus they are called power brakes. The pcv line usually attaches to the air cleaner housing, with a short hose usually about 6" long. There is a small filter which sets in the side of the air filter housing. The hose form the pcv valve connects to the filter, with a small plastic elbow. It looks like you may be missing the hose for the pcv ? I believe the 71 -73 mustang's had the pcv valve in the top of the oil filler cap at the front of the drivers side valve cover, and the hose came back to the air filter housing from there. I'm not 100% sure but I think so. Hope it helps. if I'm wrong someone else will know. JTS 71`Mach1
Here's what I've been looking at. You've got the valve (part 6A666) in the oil cap. Then connects to hose (6A664) that goes to the metal tube (6758) I just found. In this diagram it goes to another rubber tube (6N664) and finally directly to the back of the carb where in the above posts picture the brake system is hooked up.
On the passenger side on the back of the valve cover is an elbow (6767). I'm told the 73 351C and the 73 only had an elbow that was shaped like an F. This is because there was a slight change in 73 to the emission system. It didnt carry on past 73 because of the huge emission law changes made on the 74 models. This is the side that connects to the small filter inside the air cleaner.
My current set up is PCV valve in the oil cap to just the rubber hose that is laying on top of the valve cover. Then on the passenger side is just the elbow with the part that stick out broken off. Because it's broken off it obviously isn't connecting to anything.
That shows the driver side PCV going to the back of the carb. Since mine has power brakes I'm wondering if there should be a T at the back of the carb or what the setup is suppose to be. Atleast I've been reassured too that the white valve is part of the brake system. When I get home I can dig into the brakes section of the 73 parts manual and the service manual.
If you can zoom in on the fourth picture you will notice that there is a vacuum tree on the manifold to which the power brakes connect as well as three other vacuum lines.
This is what I found once I got in to the manuals. In the upper right of this picture is the power brake valve (2365). It connects to the rubber hose that is suppose to go over the shock tower arm. Then connect to a metal tube which ends up at part 9A474 which is an intake manifold vacuum outlet fitting.
So my conclusion is that there is no T for the back of the carb to support both the PCV and the brakes. It should not be hooked up to the back of the carb at all. Now I need to see if I have this outlet fitting on my manifold. If not I need to get one and see if I can find part 2420 or make it.
Ford did the pcv several different ways depending on what the car was equipped with, and I think sometimes for the heck of it. As for correctness you were right in going to the manuals. All I can say there is to be sure you match all the options your car came with, power brakes, automatic, etc, as theses things can cause differences in where they hooked things up. JTS 71 Mach1
Lots of new. Duty called once again so I'm back in the reserves as vehicle maintenance. Since I was last here I've restored my valve covers & oil pan, serviced the FMX, have a pinon seal leaking on my 3rd member, removed the dash, restored my instrument cluster (fixed the circuit board & LED upgrade), replace the oil dipstick tube and today did a compression test. New full floor pan and seat platforms are enroute. Hope to have those in and the heater out, restored, and back in by mid-June.
Sigh... Here are my compression numbers:
Driver Side Front to Rear
1 160psi 100% 11.0:1
2 135psi 84.4% 9.3:1
3 135psi 81.3% 8.9:1
4 145psi 90.6% 9.9:1
Passenger Side Front to Rear
5 130psi 81.3% 8.9:1
6 145psi 78.1% 8.6:1
7 130psi 81.3% 8.9:1
8 145psi 90.6% 9.9:1