if you are running in a new engine that has been rebuilt then the oil want to be the cheapest that money can buy and use graphite grease on all moving parts as when you first start up there is no oil on any of these moving parts ? as for running in dont do as the other guy says as you will just destroy the effort and money spent on having the rebuild you want to run it in on the move when the car is being driven not on the spot for twenty mins you need to do 800 miles at 2500/
3000 revs and no more then drop the oil and filter replace and then use the cheapest oil again and do a further 600 miles at 3000 revs to 4000 revs and no more but the more miles you do the more reliable it will be in the long run the longer it will last you after you have done this use the specified oil listed happy motoring