Breather-1,2, or none?
 

My 62 has 2 breathers, not the same. Smoke comes out of the passenger side at idle and apparently at hwy speeds since I can smell it when I run the heater fan. I replaced the passenger side with a cap from one of my parts motors. This seemed to help.

I looked at all 3 motors and they were all configured differently...

The 62 has the replaceable filter behind the drivers side cylinder head with 2 breathers.

One of the parts motors has the filter, one breather, and a cap.

The 3rd motor is a 66. It doesn't have the filter behind the head, just a solid unit with a pipe that goes to the air cleaner. It has no breather, just a cap on the passenger side valve cover and no hole at all on the driver side.

On my 62 I put caps on both sides to see if it ran any different and it doesn't but one of them doesn't seal so not a conclusive test.

What is correct for this engine? I was thinking the rear filter assembly might not draw properly with breathers in the valve covers?

I still haven't finished cleaning/painting parts to swap out with the filthy stuff on it so I could still use the one with no hole stamped in it if a breather isn't needed.