motor runs rich plug are black soot

[surfsup]

Cars running rich, ran rich when I bought it, replaced the plugs thinking maybe they where wrong, adjusted the carb that was out but it stills running rich, plugs are black, carb is adjusted correctly, timing is right, not to sure if anything has been done to the motor except for an 3 angle valve job, what’s causing this ??? Do I need a different heat range ?? Motor specs.. 86 block, 85 heads with 3 angle valve, stock Holley carb, no air pump, stock ignition, egr not connected, air tubes to h pipe plugged.