The breather/draft tube is right next to the pump. That is a big pipe, why need more? Hole in bolt is less that 1/8.
Bart, it needs to be pointed out that I do not know what I am talking about and that I am just throwing out random ideas. I don't drink any more so my answers sound stupid to ME sometimes. Anyway... the draft tube doesn't function at all at a full stop, and not much at all until some speed is built up. I was stabbing at the notion that a vacuum pump could be a neat way to evacuate fumes from the crank case at idle, when the downdraft tube isn't providing that task then. A vacuum pump on a 235 of this vintage seems odd if the trucks had electric wipers by then (?).
Carl
