The reason I brought the question up is because when I returned from Okinawa in 1964 my Dad had bought me a sweet little 57 Ford Custom from the same dealer that he purchased his new T bird from. The road draft tube was plugged and the oil filler breather was changed from open to closed and a mickey mouse pcv system installed.
That was in June and a couple of months later heading to Anaheim from Santa Fe Springs where I had dropped a buddy off there was suddenly a load bang and oil all over the right side of the windshield. The pressure in the crankcase had built up to such a point and had nowhere to go that it blew the dipstick out and put a dent in the hood. I stopped at a gas station cleaned the windshield off and added almost 2 quarts of oil and put the dipstick back in it's place.
The next morning I pulled the plug on the road draft tube, you should have seen the mess it made on my Dad's asphalt driveway, and went back to an open oil filler breather. But the damage was done as it starved the bearings and she started smoking so I sold the car to one of my buddies, he knew the history, and in Sept I went home to Ohio to pick up my 36 5 window coupe.
Oh and by the way, the road draft tube on a sbc is located on the driver's side, not the passenger side.