Same as Jack. Castrol 20W50. Haven't had a failure yet, and I've been at this for a long time.
And, Tony, you should actually vary the RPM between 1800~2100 or so during the initial run period, as it causes the lifters to rotate at varying speeds, allowing for a more uniform bedding in to the cam. Under no circumstances let it idle. If it overheats, shut it off, and fix the problem.
I generally will change the oil after 200~250 miles, again at 750 or so, and then finally at about 1500. New filters each time, of course.
Jeff