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Dead Parrot · 04-20-2024, 05:06 PM

Unless you are really set on those unvented chrome valve covers, pick up a set of 68 or later OEM SBC valve covers. They will have the proper holes for both the PCV valve and the matching air filter. (Should be easy to find in salvage yards) Replace the existing oil cap with an unvented version. My 68 Impala with a 327 had your type of intake manifold. It had an unvented oil fill cap and the valve covers I mentioned. The PCV system keeps much of the blow by crud and water out of the engine oil. Normal setup is the PCV valve is on one side and the air filter is on the other. Air goes in via the filter, across the bottom inside of the motor and out the PCV valve and into the carb base. Give the valve covers a nice paint job, install, and done. No ad-hoc fabrication needed.

Most street carbs are calibrated with the assumption there is a working PCV system installed.

04-20-2024, 05:06 PM	#14
Dead Parrot Registered User Join Date: Aug 2012 Location: Oklahoma City, OK Posts: 2,495	Re: Hard starting conundrum Unless you are really set on those unvented chrome valve covers, pick up a set of 68 or later OEM SBC valve covers. They will have the proper holes for both the PCV valve and the matching air filter. (Should be easy to find in salvage yards) Replace the existing oil cap with an unvented version. My 68 Impala with a 327 had your type of intake manifold. It had an unvented oil fill cap and the valve covers I mentioned. The PCV system keeps much of the blow by crud and water out of the engine oil. Normal setup is the PCV valve is on one side and the air filter is on the other. Air goes in via the filter, across the bottom inside of the motor and out the PCV valve and into the carb base. Give the valve covers a nice paint job, install, and done. No ad-hoc fabrication needed. Most street carbs are calibrated with the assumption there is a working PCV system installed.