I have another sbc 383 about ready to go. I'm considering changing my break in, last engine I built had less than stellar ring seal. This is an OEM roller motor with moly rings. I'm considering using 30wt non detergent oil for the first 20 minutes at 2500rpm, and for the second batch up to 500 with a few spirited runs, then 10w30 one more time at which time Ill use synthetic with a small amount of gear oil as a zinc additive. Anything to add? I have to think that the zinc might have interfered last time with breaking in the rings. I don't want another engine that is smoky under load.