Oil Pressur low? Smokes all the time..

Hey guys i an new to Duramax's, I bought my first last week, it was a rollover so i changed the cab and box and interior ect.. And took the ecm to Kennedy and he reflashed it with all the factory settings, and today i changed the oil, and decided i would drive it around a little just to see how everything felt and sounded ect. Well even after running for 15 min it smoked blue and when i gave it just a little it just poured out blue smoke. and if i get on it more it blows black?! It is straightpiped but still, i shouldnt get any black if its stock and i am in neutral and just rev it? I dont know the history on if it was run at all while it was upside down or what. But it also only carries 30psi of oil while idling and about 60-70 while running, is this normal for an 06 LBZ?