Uhm...I think thats backwards, isn't it? Prior to the 70s everything was open, right? His suggestion to me on mine was to setup a resevoir (closed system) vs allowing it to exit to the street (open).
"Prior to the '70s, the cap would release this extra pressure to the pavement. Since then, a system was added to capture any released fluid and store it temporarily in a reserve tank. This fluid would then return to the cooling system after the engine cooled down. This is what is called a closed cooling system."
So maybe the question is, does he have a resevoir setup?
