Mannifold is edelbrock airgap
There's your problem. You're experiencing the same kind of carburetor icing that makes airplanes crash. Once you get up to speed in cold weather, the airflow under the manifold cools it enough the fuel is condensing on the floor of the manifold and it's going lean when you slow down and stop. Another possibility is that there's enough of a cooling effect in the carb venturi to form ice crystals inside the carburetor from the moisture in the air because the manifold is so high and cold the engine heat can't get to it. Air gap manifolds look cool, though- - - -they're just lousy performers for street use! Maybe the Chevy engineers who designed the original-equipment parts weren't so dumb after all!
Jerry
