Intermittent crankcase pressure issues

Oh yeah something is definitely wrong for sure I just can't narrow it down and I'd rather not pull the engine this winter if I can help it. I might be able to pull the passenger side head and get a better look at everything without too much issue. I'd like to measure the pressure but I feel like it's just going to tell me what I already know.

Well if you know it then you gotta pull it, and fix it before it blows the rear main seal out...... along with half your oil........ which will do a lotta damage in just a few seconds. Or if it pukes oil on the headers instead and the car catches fire, then you are looking at a really,really, bad day.