I've always heard two different methods. Ride it, and get it up to a good running temp for like an hour, and let it cool down. Never stay the same RPM's, and keep them fairly low. Do that 3 times. Re-torque the head and jugs, and ride it. The other way that I've heard to do, is after you get it back together, ride it like you would normally. If it's ever gonna blow up, it's gonna do it right there. I've done both, and neither one has failed me. As far as oil/gas. Run what you would normally run in the engine.