Jeepwalker

Hi guys, looking to get your thoughts on something. Here's the deal:
1987 XJ, 4x4, bone stock 4.0, 135k MI. This is my snow plow truck for my own driveways (not commercial). It's always had a ton of blow-by in the 10 yrs I've had it ..to the point where the air filter becomes oil-soaked after a while. I probably put on 2k MI/Yr. I removed the intake/exhaust to fix a cracked exh leak and I see the rear exh port is fairly oily. I'll see if I can get a picture in the light tomorrow. All the stock emission hoses and lines had been in place and routed properly, no leaks that I know of. I had checked this stuff out years ago to ensure all was well, but never really addressed the oil in the breather issue.

Anyway, I read up on the CCV system and checked the small rear line. I could blow through it, there was some resistance on the valve cover side (rear), and free on the intake side. The rear grommet has somewhat broken down (oil softened) and it looked like about a 1mm hole under the grommet ...which I will replace. IDK if that's too small or normal?? Would that be enough to cause the problem? I removed the back 3 spark plugs and expected the rear one to be oilier than the rest but they all appeared fairly gas/oil soaked. None were dry and whitish/brown like I expected. None of the exhaust ports are really dry and whitish like you'd think. I didn't blow through the large CCV line (front) but I don't think it's obstructed and it was sealing well AFAIK. There's quite a bit of oil in the large rubber intake hose to the throttle body, I've cleaned it out before too.

Ok, so here's my question: What are the chances some part of the CCV system could be causing the blow-by and soaking the air filter, or does it sound like worn or cracked rings ...or something else? Are there other potential things I should or can check out to help narrow down what could be causing the excessive blow-by as it sits now? Right now, I'm looking at the engine, and by draining the coolant and uhoooking a few lines I could pull it out and stick in new rings and have the head done. But I really don't want to take the extra time to do that if it might be emissions related. So, I have a dilema on my hands... Is there anything you think I should check to figure out if my blow-by problem is emissions related or rings ...something else??

thanks in advance