Ford put PCV's on many WWII flatheads...it was set up so:
Pan vent (the original exit for system) was blocked, as the PCV was the new exit for vented fumes.
PCV drew from a plate under carb with small passages running to both sides of system. PCV itself mounted vertically on right front of the carb riser and drew from a fitting drilled up front in the generator riser part of manifold so that draw was from right over the top of the vent tube in valley.
The inlet was the same as stock on the fuel pump riser, but the filter was replaced with a much larger oil bath unit rather like a half size replica of the carb air cleaner.
On a stock 59, many truck manifolds have a large plugged hole (meant for power brake assist) with two small passages connecting to the two plena. This would be a neater hookup than the plates I have seen. Stock 59 car manifold has a flat for this passage that could be drilled pretty easily for hookup.
Aftermarket manifolds generally lack a decent place to connect to both passages, and the plumbing from underneath makes a lot of sense for these.
(there is a picture of a stock Ford PCV setup in this thread:
http://www.fordbarn.com/forum/showth...n+pcv+military )