Re: how bad is this?
You could use "extractors" to vent the excessive blowby.
Goto Jegs (jegs.com) and look at part #720-6002.
commonly used on late 70's ..early 80's GM ..developed by Grumpy Jenkins to relieve crankcase pressure.
Cheap stop gap measure ..especially if you don't have other drivabilty problems (the pinging is probably because of the oil).
Now that I've quit smoking my doctor informs me that I'll die in much better health!!!