Engine Engine oil from breather.

[ram137]

I have an 85 with the 258. 84k actual miles. The jeep sat for many years. It runs well now, but at high RPMs engine oil is blowing out of the breather and gasket around the pcv. I’m thinking I need to replace the valve stem seals. Does this sound right?

 

[CJ]

Sounds like a lot of blowby, most likely caused by a stuck ring because it has been sitting for a long time.
Bad valve seals would show as alot of blue smoke in your exhaust because of oil getting in the cylinder. They do not control blowby.
A quick solution that might work could be soaking the cylinders in some Marvel Mystery Oil to try to free up the ring BUT first run a compression check to see if this is your problem.
It's unlikely but the valve guides may be an issue.
First thing to do is a compression AND leak down check .