The catalytic converter and carb are new within the last two years. I replaced them both, along with the air pump to pass smog and register the vehicle in CA. Yes, the carb was a Holley remain from Auto Zone or Napa. It was nearly $500 with the particular water choke and smog ports. Perhaps, I need to have it inspected. I clean it regularly and performed a 'lean drop method' to get the idle mixture and idle speed just right. I currently have the truck at 8 degrees BTC at approx. 800-850 rpm at normal operating temp. I am no carb expert though, but it seems like the most logical problem source. My mechanic is pretty good with carbs. I will see if he can look at it.
