well PVC blows stink out, rather than sucks it in. There should be somewhere on your intake manifold a place where you could get some vaccum for the booster. The engine acts like a big compressor in a way, in that it sucks air in through the carb, and blows it out through the exhaust (anyone remember those hoses you could put in a sparkplug hole to air up a tire?).

on my 292 there is a tap right near the base of the carb.

be sure to use vaccum hose otherwise, the other kinds of hose can collapse under vaccum and then you don't get any power brakes.