Quote: And if this Holley is burning excessively rich at idle, would that have a negative effect on the fuel economy as well?
heck yeah!
OK, we're back where we started with the Holley...which was checking your timing and being sure that retarded ignition timing wasn't causing excessive curb idle throttle plate opening...
Check the timing and let's be sure that's where it should be before we decide the carb is the culprit.
