I removed the draft tube from my 58 and installed the pcv valve directly into the engine block. I also made a catch can from a glass baby food jar and installed inline before the intake. There was so much oil mist collecting in the jar that I measured 6 oz. in 300 miles . I removed the pcv from the block and installed a 10 inch piece of 1 inch electrical conduit with the pcv valve in the top inside a grommet. I still used the catch can jar . I have driven over 1500 miles and have collected only about 1/2 teaspoon oil. That catch can made from the small glass jar let me see everything as the engine was accelerated. When the pcv was directly in the engine block upon acceleration of the engine there was a visible fog inside the jar ( oil mist ). Now there is nothing visible while accelerating. My engine is a 1955 235 recently rebuilt.
I installed a PCV directly into the draft tube hole in the same manner. I didn't install a catch can but noticed when I pulled the vacuum line off at the manifold oil would literally drip out of the line and out of the fitting in the manifold. I then cut the down tube portion off the draft tube and installed the PCV there, no more dripping oil. The lowerend of these engines generate a tremendous amount of oil mist by design, primarily to lube the undersides of the pistons, cyl walls and around all the rotating/moving parts.
