Some engines had a valve cover that vents on the top at both front and rear of cover, some had solid covers. I had a solid cover on my 235 and my 261. My answer to the pvc situation was to get a oil cap that had a pvc connection on it, then ran a hose to the intake manifold just below the carb. Been that way for years and no problems. Yes the draft tube was removed and a freeze plug inserted in it's place.
