What are the 1999 Chevy Astro Van Towing capabilities?

I have the same van. There are different gear ratios in the rear end that give you between 4500 and 5500 lbs towing capacity. Take the vin number to the dealer and they can give you the tow rating. Be warned that when I towed a 4000 lb trailer for the first time I had to have the rear end rebuilt. I threw a bering. Maybe a coincidence, maybe not.