Well just completed this mod and I'm a bit concerned - vacuum increase is HUGE compared to before. It's enough to collapse the hose coming out of the PCV valve slightly. I mounted the valve vertically with a loop of 3/8 inch hose. There is so much vacuum I can barely get the oil cap off - much different than this morning prior to the change.

I will say the CCV I think was the original from 13 years and 138K miles ago, so it may not have been working as new.

For those that have done this - did you see a tremendous vacuum increase?