Runs a bit lean...

Bad PCV stealing too much vacuum? Block it off to test. Spray water from a squirt bottle around intake gaskets, carb base, and any other potential areas while idling and see if idle drops. Some use carb cleaner or starting fluid which I would NOT do. I had a rubber cap on one of my carb vacuum ports that dry rotted off. Maybe fuel pick up sock collapsed. If it's a bad vac. leak you might hear it. I'm no expert but I check that stuff easy enough. Or Post #4