I felt like this one deserves a separate thread because of the universality of it. I'm trying to re-plumb the vacuum lines for my Jeep. It has a 1975 vintage 232 engine. That means it has an EGR, a CTO with 3 legs, a charcoal can, a PVC valve, a Carter carb with two different vacuum ports (one at the very bottom, right at the gasket, the other further up but still on the lower third of the unit). It also has a LARGE port on side of the intake manifold, a SMALL port on the top of the intake manifold (and it's crimped shut), oh, and the vacuum advance on the distributor. That's 11 ports in total! Generally, it all makes sense if you can figure which vacuum is where. The TSM talks about straight manifold vacuum and "ported" vacuum. And to make matters even more interesting is the operation of the CTO. The center port is connected to the "1" port when the coolant is cold, and it shifts to connecting to the "2" port when the coolant is hot. I know that the LARGE port on the intake manifold uses a large hose to connect to the PVC. I have never seen a T on that line in my experience. Put together with a tube from the air cleaner to the rocker cover, that's the crankcase air flow. My TSM doesn't explain the use of the two vacuum ports on the carburetor. It also doesn't talk much about the CTO - I know the distributor goes on the D port (the center) but which vacuum is used when the engine is hot, and which when it's cold? And, to top it off, there's that crimped-shut port on the top of the manifold that might have gone somewhere. So, wizards of the less than atmospheric pressure, what goes where?