I have a 250 valve cover with three holes, two on top, one on the side. The top rear is PCV valve, top front is oil fill, side is breather pipe to air cleaner. I need the fitting that goes in to the side hole or a plug that fits the side hole. The valve cover has Chevrolet stamped in the top if that helps date it. I have been hunting the web for days and can't find a clear picture of how Chevrolet ran the breather line into the valve cover. I have seen some pictures with a big hose from air filter to valve cover, but they are not clear enough to see how it fits, and why does it need to be so big? The PCV valve uses a 3/8" line, why would the inlet need to be 1" line? I have it set up now with two push in breathers and the PCV going in the side hole. All I am doing is pulling air in the front breather right into the PCV valve, it's not really clearing the block. I want to switch to rear hole for PCV so the system clears the block lkie it's suppose to, plus I have purchased four different NOS inline six PCV valves for testing ( all AC Delco valves ). Chevrolet used four different valves through the years for the 250, so I wanted to try them and see if there is any difference in how the engine acts or what the air/fuel ratio does.
