Has to be fuel running too rich. Sooty equals too much fuel, shiny black too much oil, grey, too much coolant. If it's fuel, go back to checking out your carb(gummed up? float level off?) Also could be bad spark, so check ignition system components. Since it loads up so fast, must be fuel delivery.

Where Are You From? orygun

Do You own a car built by Durant? 1939 6-14