Texasdoc Couple of quick questions, who piston rings are you running and where they gapped correctly? Is it possible you have the pcv valve up side down? This is easy to do. Is it possible you have a set of piston rings with the end gaps lined up? A leak down test is not going to show you alot some times. Need to add a little
oil to help seal the rings to the piston walls for a better reading. Rick L. Ps before pulling this motor apart is there any way you can get a good low pressure gauge and mount it to the PVC location and lets see what the pressure reading are. We may be over thinking this and going down the wrong path.