Well, I had completely removed the PCV and capped the line running from the PCV to the manifold (as per crawford's AOS instructions). I'm running the Grimmspeed AOS, and they recommend leaving the PCV in tact. I just don't know... I wouldn't be experiencing problems for the reason you outlined because manifold pressure couldn't travel out any more... we'll see I guess. Should find time in the next couple days to button things up and take it for a spin.