Before you start it, unplug the distributor and crank it over a bit to get oil pressure in the engine and get oil circulated. Then let it idle for a bit after you finish the ring/piston/bearing install to let the rings seat. After that, just drive it normally. A lot of documentation about no break in period has been put up on the web lately, and I agree with it 100%. Check this out http://www.importbuilders.com/breakin.html