Cummins Big Cam 3 leaking oil around manifold

Wondering if anyone could shed some light on this for me. I have a cummins big cam 3 that seems to want to push oil out of the manifolds. Began the other day I started the truck up and had a insane amount of exhuast smoke. Once I drove a bunch it burned it out. Anyhow when I got home I noticed oil was seeping out heavily around manifold. Took off the turbo and lots of raw oil also pulled manifold and atleast 3 cyl were very wet. Started it up for a minute and once I shut it down the oil started running out of the exhaust ports.
Can jake issues cause this? keep in mind this has now happened a couple times so it seems to stop and start.

Thanks

 

Thanks for the info. I have already put a new turbo on. This was the first thing I did since it looked like the easy fix due to where I first saw the oil. I have also thought rings but since it doesnt happen all the time it really shouldnt be rings. I have been thinking valves. I am pulling it apart today and going to have my heads looked at and look over everything else.