Clarify if you mean intake pipe or intake manifold. There's no vacuum in the intake pipe as far as I know...

 

The intake pipe, I read that the turbo pulling air in would create a small vacuum in the pipe therefore sucking air through the CAN via the VC. I see now that the balance shaft hole is already tapped, my problem is my can is set up with barbs not AN's. I didnt want to have to buy a new can. Also your saying the closed can is better at lowering crankcase pressure? Sorry or all the questions, just got the motor built and now running into these pressure problems and trying to alleviate them...