You say you have white vapor from the vent tube. Is there a milky brown snot like goo in the breather tube? If there is then you are getting antifreeze in the oil. That can be from a leak in the head or a bottom liner seal.
I think I broke it in properly. I am using brake-in oil. I used it at 2300 rpm for about 3 hours straight chisel plowing. I had a brake line pop so had to stop for about an hour to repair, the engine was still warm. I then used it for about 6 more hours chisel plowing. I have used it to disc plow and shred since. I noticed white exhaust at low rpms recently as well as the blow by. I did not see these initially. What is the compression test supposed to show? I paid a lot of money for the rebuild and do not feel I should be paying again. Am I correct/
What is brake in oil?
It is a special formulated oil that is lacking certain anti wear additives to aid in seating the piston rings but still giving adequate lubrication to the rest of the engine. John Deere sells break in oil and recommends it for all new and rebuilt engines.