u do have that wire mesh under the pcv valve right???......to check for blowby supposedly u can just take off the oil cap with engine running and see if u feel positive pressure
change the valve. I had blowby on my 347 stroker from rings that did not seat properly. The blowby pushed the dipstick out of the holder by about 1/2".
I have never heard a cracked ring will make ur motor puke oil out the PCV valve.
i have replaced the pcv and thats what i had read or the rings worn or thw cylinder and on the compression strok all the pressure will go to crank case and out pcv