Opps my bad. . . alligator/hummingbird.. I forgot about the second hose we put from the valve cover to the aircleaner and all the little air filters I replaced inside the air cleaners of those 70's Chev's. I remember removing all the draft tubes and sealing them and testing the PCV valves so they could not send a fuel mixture into the vapors of the engine..
I still suggest the use of a PCV valve to keep the "aroma" away from the passenger compartment and they do help keep the engine clean..The vacuum pump was a secret 20 years ago but not anymore.................JD
