The the image above for the closed type system used to be called a type 4. One hose from the PCV to the carburetor base or spacer with a PCV fitting and the other hose from usually an
oil filler cap to the air cleaner. This is what I have on my roadster and went through the visual without a problem. These
oil filler caps can be bought through Mustang or Ford aftermarket parts dealers. But, everyone seems to have a different experience when taking their cars through the BAR referee station.
Just a note here, there was a retrofit program in the mid 1960’s in the more populated counties in California that required certain items be installed on cars dating back to 1955. One was the crankcase retrofit which routed blowby from the crankcase to the intake manifold and the other was the exhaust retrofit kit which basically was a kit for keeping you distributor from advancing when certain conditions were met.