crankcase evacuation?

Get a PCV grommet that fits the V.C. & the valve snugly, otherwise you're not developing enough negative pressure(vacuum) in the crankcase because the air is just getting sucked in around the grommet instead of pulling it through the crankcase. It needs to be able to pull air through the whole system from the breather on the opposite side in order to properly evacuate the crankcase. This could very well be the cause of your main seal leak problem too. Seal that PCV up good & your problems will probably go away.

If you want to check the efficiency of the system pull the dipstick & connect a vacuum gauge to the tube, block off the breather & check vacuum. This should be a quick check not a prolonged experiment because you don't want to suck the seals/ gaskets inward if its working right. You should see something close to manifold vacuum at the gauge. Next do the same at the breather hole w/ the dipstick back in place. Same thing.