Connecting into the brake booster line will not be a problem. Vacuum is vacuum, and it all comes from the manifold regardless of where you connect. The PCV should not be connected to a ported vacuum source. The valve itself will control the flow. Also make sure you have a fresh air source to purge the crankcase, whether it be a line from the rocker cover or crankcase to the air cleaner, or a filtered oil fill cap. You need a "loop" for the PCV air to flow through and purge the crankcase. The PCV system only flows a few CFM of air at most (4-6 CFM max. as I recall).
