I ordinarily go with how GM does things, so I was planning on filling my freshly rebuilt LS7 with Mobil1 and changing it in 500 miles. My engine builder has a whole procedure for that:
John, We run the engines on the dyno to break them in with Gibbs or Brad Penn break in oil, we then drain it, cut the filter open to check for any nasty chunks, then leak it down, if all is good on the leak down then we ship it and recommend Mobil 1 5w-30. Kurt doesn't seem to be too particular about any one brand of oil.
Hey John - Im curious what cam choice you made for the new engine. Im thinking of sending my heads to Richard at WCCH and currently use the katech torquer 110 cam. Really like the low end grunt this cam gives but think Im giving up 50 to 75 hp on the top. Can you tell us what mods you made to your 427?