A small amount of smoke after starting is normal due to the valve stem seals. They get hard with age. I will recommend a full diagnostic before tearing down the engine. Lots of things it could be that don't require major surgery. Check the points and plugs. Compression check will tell what the rings are like. A leakdown test on each cylinder will tell if the valves are seating. Hook up a vacuum gauge, it's a wonderful diagnostic tool. Vacuum gauge tuning


Fred
52 3600
69 C-10