A simpler, and much less expensive option would be to plug off the port at the back of the block with a freeze plug, and use later model valve covers with baffles and grommets for a more modern PCV system. Just because the earlier model vent system with the pushrod valley baffle can and the road draft tube hole is there is no reason it has to be used. Air flows into the engine through one valve cover with a vented oil filler cap, flows down into the crankcase, and exits the engine through the PCV valve inserted into the grommet in the other valve cover. Simple and efficient, and all the parts are available at the local FLAPS- - - - -no scarce and expensive adapters involved!
Jerry
