I agree with 52Carl, it is not uncomon for engines to smoke after rebuild and long rest periods until all the accumulated parts have heat cycled to operating temperature several times. Ring seating can take some time. To get a full temperature heat cycle you probably need to drive it at least 5 miles let it cool completely and repeat. Ring seat best when power is cycled, not just rpm, as you want to change the combustion pressure acting on the rings to change.
The fact that you are not loosing any coolant is a great sign.
