pressure build up

[dogman44]

hello,, so this is my first post. question is, 49 Massey fergison,65,w/g176 gas engine. I just replaced the head on it adjusted the valves,warm to .16 intake and 18 exhaust. I started it to warm it up to adjust the valves, after about 5 minutes I noticed oil dripping from the dip tube. I shut it down, and pulled the dipstick out, a little oil. but a big discharge of air. I done a compression test dry, got 155,150,150,150,wet test157,153,155,can 0nyone tell me what might cause the pressure build up

 

[used red MN]

This new member mistakenly double posted this. In his other post he has determined that he accidentally made his own gasket which was solid where the breather tube attaches to the valve cover. link to other post