I know a lot of guys who are using Shell Products Rotella - T in 30 Wt. to break in their race engines as it has all the Phosphorus, Zink and Sulphers that the old oils used. That is what I am going to use to break in my Chevy with. Kendall still makes the oil with the old ingredience in it I believe but expensive. Rotella -T can be brought at Walley World fairly cheap.
62Blue

62Blue
62Chevy in progress
You've never been lost until you've been lost at Mach3" Paul F Crichmore (Test Pilot)