to purge the crankcase you dont have to have anything connected to the crankcase proper as the fumes can be evacuated out through the valve cover. The oil drain holes in the head provide a passageway for the fumes to be pulled from the crankcase by vacuum. Perhaps the fumes were drawn only by the slight vacuum at the carb airhorn. The pcv systems for 235s had to have been a Calif. only thing as pcv for the rest of the nation did'nt come out until the '63 cars. (no more 235s by then)
