New member with an oil leak question

My son's 90 4.0 has an oil leak that I'm trying to diagnose. The emissions junk has been removed from the rig, ie the airbox, etc. The forward hole in the valve cover I believe originally contained a tube going to the factory airbox/intake, but since the removal of both of those items, the po stuffed a chrome "Mr. Gasket" oil breather in that hole, which now appears to be puking oil out while driving.

SO, the question- is this to be expected with a jury-rigged setup such as this? OR, do you think there's some engine problem causing excess pressure under the valve cover and expelling oil out the breather?

Thanks!
Tony

There are two breathers. The other one plugged?

I'll check into that tomorrow- thanks!

check rearmost (firewall side) breather, it clogged and make pressure thins to make blow by.