Blows the seals out or sucks them in???
Do you run a vacume/pressure guage hooked into your valley???
do you have mufflers on the car??? Crankcase evac won't work with mufflers, you'll just pressurize the crankcase instead
do you have your intake hooked up to vacume your crankcase??? My tunnel ram engine would pull a strong vacume at idle and the headers evac system would then take over and pull 18-20 inches in the traps at 9500rpm