Loop the vacuum line up near the top of the firewall before routing it to the booster under the floor to prevent oil from getting where it doesn't belong. The PCV has a pulsating flow and it shouldn't interfere with the vacuum going to the booster. Most brake boosters have a one-way check valve built into the fitting that goes into the vacuum chamber, so there's at least one brake application with power assist available in case of an engine stall.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!