I wonder what the results of rigging up some sort of evac system on one of these motors would do?
That's basically what you are accomplishing (though a really low performance version) with the PCV setup. Negative pressure in the crankcase pulls the rings out against the cylinder walls, increasing ring seal and reducing blow-by.
It is quite common in racing circles to run a crankcase evac pump to create (and hold) the crankcase in a negative pressure state to take advantage of the increased ring seal, reduced blow-by, and subsequently, the increase in power output it provides.
While the PCV does have the potential through vacuum to create some negative pressure in the crankcase, as an engine ages, and blow-by increases, this can easily be overwhelmed. And where you would benefit from the increased ring seal the most: with the engine under load, at WOT, since you have no manifold vacuum, the PCV is doing nothing more than acting like a breather for blow-by gasses.
IIRC, the Camaro's of certain years had electric vacuum pumps on them. These are often converted into cheap crankcase evac pumps for budget race setups. I would be quite interested to see what the result of running one of these on one of these cars would do.