Yup. That's how a lot of V8s get their oil. Not sure if a plan breather is much different than a breather-oil cap or not...
My dad's 318 in his Plymouth Satellite had an oil cap with a hose to th air cleaner. Just pulled off the tube mounted to the top of the valve cover.


Current fleet (subject to change w/o notice)
\'49 GMC 3/4-Ton , 60 Austin Healey Frog-eye Sprite (some assembly required), 2011 Dodge Avenger, 2015 Jeep Cherokee. No, they don't all run.
My other ride is a (B737)no, (B767)no, A320.... Update... was Embraer E190, now Boeing B787.

Knowledge is a wonderful thing, but ignorance means you don't know you can't do something.