C 20 3/4 Ton Pickup 2WD V8-379 6.2L DSL VIN C FI (1983)
Positive Crankcase Ventilation: Description and Operation
All engines produce small amounts of blow-by gases which seep past the piston rings and into the crankcase. These blow-by gases are a result of the
high pressures developed within the combustion chamber during the combustion process, and contain undesirable pollutants. To prevent blow-by gases
from entering the atmosphere while allowing proper crankcase ventilation, all engines use a PCV system.