All white and alot?
A little white and only at start up
All blue and all the time
All blue and only for the first minutes at startup or when you floor it
All black and alot of it
All black and only on start up or when you gas it hard
Some mix of the above flavors?
Since you mention rings I am assuming it is oil smoke, Another major source of oil burning it the valves, particularly the guides. The original heads were designed for leaded fuel, the lead was a lubricant. Modern fuels do not have this and will cause the heads to wear excessively (if a 40 year old head can be worn prematurely).