We'll I finally got around to the teardown of the engine to determine the valve tapping and smoking. First I did a compression check. All cylinders were just around 170. All the plugs , when removed had black carbon. Carb probably adjusted too rich. Number 8 cyl. plug looked a little oil fowled. Possible smoke origin. Number 7 intake pushrod was demolished where it fit into the rocker. Pushrod had crumbled into pieces and has shortened the pushrod by 1/4". There a good reason for a valve tap. I've never seen a pushrod crumble. The rocker arm socket still looks like there is no damage. I guess I'll drop off the heads at the machine shop and have them go over them. Pistons and valves are coated with carbon.