Tonight, it topped out at 11.7 psi. I thought it was a fluke a couple of days ago when I saw more than 10. It started out in the 9 neighborhood after a couple of tanks of gas with the new motor. I am thinking that the severe oil blowby problem that I am soon going to remedy is the culprit. We tore the oil baffles out of my valve covers for the new rocker arms, and I am running PCV. I ordered an LS6 valley cover, I hope it fits. For now, I have an air-compresser coelescing filter in the PCV line. It fills the 2 oz. cup in about 100 miles. I was too lazy to empty it before tonight's test, and the blower probably got a few gulps of oil. I drilled and tapped the blower's intake elbow for a fitting to introduce PCV, because it's the only place that sees only vacuum, never boost. All this explanation leads to my question:
Does anybody else think that the oil would cause my boost to rise? I mean, if enough got into the blower, could it improve the seal enough to get 3 more psi? I know screw-type air compressors are oil sealed. Yes, I was getting a lot of KR, running 10.9-11.2 AFR. OK, my typing finger is sore.

 

If my cats were getting clogged, it couldn't possibly run this good. (?)

 

Cats? What are those? Oh ya those furry little creatures. Its possible the oil acted as a seal like you were describing.