Blowin' Smoke! Please Help

Thank you all for all the help. Im gonna purchase the tune up kit and try adjusting the choke, and hope I can make it a little leaner and cross my fingers that its not bad rings. This is the 4th motor I have built, and all of them have burned rich yet none of them had ever blown blue smoke. I feel my timing is right were it should be. It idles great, runs great, and is set right at the point before it starts pinging. I just went out to check my valve covers, and they do have the shields on them. Thanks again. Kory