Phak1, yes, that is the standpipe I have but you're incorrect about the valve. This PCV valve is not a simple check valve, it has a movable venturi with a small hole in the center that is connected to a spring inside. Under high vacuum the venturi is pulled open by vacuum allowing a larger amount of air to flow around the venturi. Under low vacuum the spring pushes the venturi to the closed position only allowing air to pass through the small hole in the center. At least that's my understanding of how it works. Actually I think I have that backwards. The valve closes at high vaccine and closes at low vacuum.
Bouymaker, thanks for the info. I'm running a 1954 261c.i. bored .040 over. The original PCV threaded into the top of tube that replaced the road draft tube with a steel line to the intake manifold. I'm not sure what would make the PCV that I'm looking at "heavy duty" but I'm going to run it.
Last edited by Chevy's till I d; 04/20/2021 11:31 PM.
