How do these compression numbers look?
 

Hi, I initially posted this question on the technical forum, but have not had much feedback yet. My apologies for posting here also.

My 66 2.0 is leaking oil out the breather vent after running the car for a while. It did not leak after a 10 minute idle, but it did after a 10 minute drive. At that point the oil seems to be blowing out the vent.

At the suggestion of John C. I did a compression check. Here are my compression numbers.
130
121
118
110
111
120
Would these explain the oil blow-by? I was expecting the compression to be lower. While I am sure that the engine could benefit from a top end rebuild, I would rather not start it at this time. I am in the middle of a 2.2 teardown and would rather get that one finished if possible. Another friend suggested that since it only seems to leak when hot, that maybe the oil thermostat is not working, or possibly the oil cooler is blocked. Anyone have any ideas?
Thank You,
John

Your numbers are low. I would say it could be worn or broken rings, causing the crakcase to be pressurized. If you can do a leak down test you will have a better idea. I wouldn't drive it till you have a better idea.

Yes, your 2.0 engine is tired and in need of some top end work.
A leakdown test will likely tell you what you already know, lots of byass from worn rings/pistons/cylinders from this 44 year old engine.
Time to get busy with the 2.2.