After the initial 15 to 20 minute break-in, you need some drive time to break-in the rings and seat the bearings. Usually 4 to 5 miles is enough and what I recommend to my customers. The rings need loaded under acceleration and deceleration. Bearings tend to take of them self. If the engine has a filter, you can always throw a new one for piece of mind after the break-in. It's tough to drain expensive oil, but that's the cost of building and running old engines.
