Idle mixture screws......one turn out not enough?

[Fairlane514]

1970 454 oval port motor with slight upgrade cam (Comp 268 extreme energy), stock otherwise.
Motor is fresh rebuild with less than 300 miles.

1 1/2 turns out now, puff of smoke out of the exhaust when you rev it up. 

Question: I'm thinking to lean it a little more to one full turn out from all the way in. Is one turn too little? Maybe the piston rings aren't seated yet.  The smoke is not blue and smells more like unburnt fuel and not oil burning.

[77cruiser]

Try setting it to the highest vacuum & lean it an 1/8 to 1/4 & see what it does.