1929-57 Chevy Master Parts List Section 1.745 49-57 ALL 6 cyl VALVE, crankcase ventilator 1544935
1961 Chevy Parts and Accessories Catalog 1544935 USE 5647228
1971 Chevy P&A 49-61 All (6 cyl.), 5647228
Originally the crankcase ventilator was intended for military use but was also sold as an option to use on cars and trucks (RPO 217) for use in a dusty environment. Beginning 1964 to 66, California adopted a PCV requirement for new and a retrofit to most 1950's cars and trucks. Later on the EPA required all new cars and trucks to have PCVs.
The valves are ENGINE SPECIFIC and I would use what Chevrolet listed. The AC catalog says the CV469 (GM 5647228) is a "replacement" valve for "heavy duty" usage. Like the original OEM Chevy valve, it is made to fit the road draft tube with the threaded hole.
AC also lists CV208 or CV609 and CV695 for retrofit. Some have hose connections. Some screw into an adapter on the intake manifold. I haven't looked into an alternative valve but if you search this forum you can find a lot of PCV information. I prefer the original RPO 217 look but some prefer to hide the metal lines or rubber hoses. It's all a matter of taste.
Does the steel PCV valve work? Definitely! It's currently on my 55 1st with a 261 that came out of a 6400. You can take the valve apart for cleaning which is something you can't with the new valves. Is a PCV beneficial? Yes. For the health of the engine. The thing that makes the valve fail is an oil-burning engine where blow-by sludges the valve till it can't operate. It that case any PCV is useless.
Last edited by buoymaker; 04/20/20219:08 PM.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
