The PCV valve was introduced on some engines in 1962, and on all vehicles starting in 1963. All your engine may need is a road draft tube to draw pressurized combustion air from the crankcase. All engines have a certain amount of ring blow-by which pressurizes the crankcase and forces oil vapors out of the breathers. Even too much exhaust back-pressure can cause oil vapors to be forced out of the breathers and can saturate the firewall with oil.
Last edited by MouseFink; 12-05-2012 at 12:08 PM.