[68c10airstream]

Under the assumption it's a tbi 4.3, lift up the throttle body by removing the 3 bolts and replace the tbi base gasket. It's leaking air in under the base. If you are handy you can still leave the fuel lines and everything else attached. I'm handy because i'm not handsome. That's what i tell my wife! Ever seen a good looking plumber? Mechanic? Maybe on tv, but not in real life.