Its not forced induction. Could the port on the intake where the pcv is at get stopped up? Not sure what its called but the path that the gasses flow from the crankcase through the pcv.

 

Does your actually have a pcv valve? Or is it the fixed orifice type of deal.

Easy Enough to test though. Pull the lines, see if you can blow thru them. The fixed orifice feller might be plugged up as well.

 

The pcv is the kind that twist locks in the intake. There is no hoses. It all inside the intake. Thats why I ask

 

Hhhmmm....... I think that would be something to investigate.....

 

Yea I'm going to pull it this weekend and see if I can see anything.

 

I would be asking whoever rebuilt the engine how they seated the rings. There should never be any pressure in the crankcase. The vacuum from the intake is what pulls the air though the block and into the air stream to the engine. Just how did they rebuilt it? Paint job only? I would be very mad.

 

Remove your intake off (not intake manifold) and see if it is still blowing off the oil cap. Double check your vacuum system. Maybe 2 hoses are mixed up and causing excessive pressure.