To find the exact towing capacity for a *specific* 2014 Chevrolet Express, you must check the sticker located on the driver's side doorjamb. This sticker lists the vehicle's specifications, including its maximum towing capacity.
Without knowing the specific trim level and options, I cannot provide a precise number. However, it's safe to say that the range is likely between approximately 6,000 lbs and over 10,000 lbs. The heavier-duty 3500 models will have the highest capacities.