With the calibration for the 292, you're too lean, not too rich. Larger engines pull more air through the venturi, raising the venturi vacuum for any specific RPM. Generally, a carb for a larger engine will have a lower float level, and leaner jetting to prevent an over-rich condition. You could probably cure some of the cold-run problems by raising the float level slightly, and going to a little richer jet, but the heat riser needs to be fixed first! Spark plug condition and color is a good indicator. A tan to chocolate-brown color is about right, black is too rich, white is too lean.
Jerry
