The Stovebolt Site Forums The Shop Area Engine Shop 47-55 1st, Are there 2 types of breather pipes ?

A closed valve cover is a necessity for a PCV system (no slits and a non-vented filler cap are requirements).

The first standard-equipment Chevrolet truck PCV system was on the 1948 3742 Forward Control Delivery Chassis model. Later, the PCV system was either an option or standard equipment on larger trucks ( depending on the truck, the engine, and the year).