Make sure the Vcan is hooked up, Fire it up, immediately get the Rs up to 2000, then immediately advance the timing until the rpm no longer increases, and back off a smidge. Then reset the speed to 2500. Do this as quickly as you can, but don't panic.Do not worry about the actual timing number; at this point only you care. Then continue the break in, varying the rpms as others have said; watching for leaks (especially fuel), and overheat. Afterwards ....... you can reset the base timing
When I do this I remove the thermostat and take it apart and reinstall just the washer part. I don't want no surprises. Actually I have a few of those "washer-restrictors" in the toolbox, but you get the point.
Keep the water hose handy to mist the rad if the temp seems to be getting out of hand. The fan will pick it up and mist everything; it's just water, let it fly.
Bring the RPM down to idle, BEFORE you shut it off.