Distributor filling itself with oil

inertia said

As throttle/rpm increases, manifold vacuum decreases till none, after that, blow-by increases to overwhelm that small pcv hose.
Normally plumbed the excess crankcase pressure blasts up the vent tube, filtered into the air cleaner, then into carb and burnt.
You need the vent to relieve crankcase pressure at rpm, or it'll blow oil out the dipstick tube, and everywhere else it can, including uphill into the distributor .
Good luck .

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I agree. I also think that load is a contributor to a decrease in vacuum. Example: Throttle position remains constant at part throttle, if the load increases the rpm can decrease and vacuum will decrease. What I have observed on the dyno is that both load and increased rpm can increase blowby. The pcv system is most efficient at high vacuum, low load and low rpm. Which depending on the driver is where street driven cars spend most of their time.