PCV Valve- Connect it to the carb or the intake?

[70_F100]

When it comes to vacuum port access for PCV and Brake Boosters the PCV is best at the carburetor since there is flow from the crankcase. The PCV system is a controlled and designed vacuum leak to control HC's, hydrocarbon's. This controlled vacuum leak is best if shared with all eight cylinders instead of a few. Allows for equal fuel misture to all cylinders when connected to the Carburetor. Their shouldn't be flow from the booster since it only provides vacuum for boost and not flow. You could use a manifold source for the booster. If it runs rough the booster may be leaking and would need to be replaced. Simply pinch hte vacuum hose going to the booster while engine is idling. If the engine RPM changes and the engine smoothes out the booster is leaking. Concerning PCV systems you need fresh air to replace the vapor the PCV valve is drawing from the crankcase. That would be the other hose attached to the air cleaner housing and valve cover. You could use a breather only on the valve cover if your using a Chrome Air Cleaner without a provision for a hose to hook up to. The reason for running your breather hose to the air cleaner was an emissions function. This is called a type four, closed crankcase system. This prevented the HC's or raw gas vapor from the crankcase from entering the atmosphere when the engine was shut off. Another thing about PCV systems, many engine oil leaks can be blamed to poorly functioning PCV systems. If you see a valve cover gasket or oil pan gasket get sucked in the fresh side of the system could be plugged and the PCV valve is putting a large vacuum on the engine and finally a gasket gets sucked in so it can breath. If the system is entirely plugged it can blow out seals. I replaced a one piece seal on an engine because it blew out. After the repair the new seal blew out in 5 minutes. I learned a lot about PCV systems that day. Might be more information than you wanted but hope it helps.

Couldn't have said it better myself!!!