I'm using 3/8" for the PCV also, and its run up to the center connection on the intake where the wipers usually go.
Rason i asked about mor connections is that i found if you tie the wipers and PCV together, the wipers may no longer work. Depends on your vac signal. Either add another hole elsewhere in the intake, or convert to electric wipers.
When you set your idle with a vac gauge, I would suggest that it not be tied into the same spot as the PCV either for similar reasons.
Drilling a hole in the carb insulator and pressing in a tube is one way to provide a source for the vac gauge. Just get a rubber boot to cover it when you're done using it.
My truck will be at the convention in June.
