If you continue toi run a new engine in so easy with no boost, it WILL smoke forever, give it some stick, don't be afraid, go easy just for first 100 or so, but mine are all at max rpm in short bursts by 500 miles.
If run in too easy they bores will glaze over, stopping the rings from bedding in correctly.
Also I hope you are using MINERAL oil, and not fully synthetic, if not change it now, as won't run in correctly/well on fully synth.
tabetha