i wouldnt worry about blow by unless you are smoking like a freight train.

my latest build that i just decommissioned had ZERO blowby, it was pretty wierd. i had the line off the valve cover and NOTHING was coming out, air, oil, i just left it open haha. I could open the oil cap and look down in to the valve cover and see the cam spinning without getting air or oil shot in my eye. It was very calm inside, like a storm was coming inside the head. lol