Did you tap into the rear valve cover at all? I'm curious to see if this works to pull the air out enough.

I picked up another front valve cover to install on the rear. I'm going to drill/tap both front and rear oil caps and run nylon tubing from pre-turbo (facing into the air stream) to the front valve cover, then exit out the rear valve cover, through the catch can, and then back into pre-turbo (facing away from the air stream to create a vac).

Here's my parts so far: