Oil in the exhaust can come from different things, Loose valve guides, rings not seating, and now from the fuel itself. And if you added oil to the spark plug holes when you did a compression test. White smoke can be steam as mentioned above. And it can be from a very rich mixture. Black smoke is usually oil. Check for water first. Pull the plugs and see if some are dirty, and some are clean. Steam from a crack or leaky head gasket will clean the plugs where the leak is. Watch for water or antifreeze in the oil. That can cause all sorts of expensive harm. If the plugs look about the same, and there is no water in the oil then I would be tempted to run at idle until fully warm with the valve cover off. If the oil turns muddy you have water leaking. if you just get white smoke, try adjusting the carb. It may have a bad float level and that is easy to fix. Drain the fuel out for certain. Use fresh gas, and keep an eye on the radiator level. Just leave the cap off and watch for any drop in the water. The rings may seat if it has not been run for some time. You can get white smoke from water in the muffler as well. That would be from sitting, or from a water leak. One sure way to determine if water is leaking is to pull the dip stick. If the oil level went up you have a leak. Let us know what you find.
