To find the exact towing capacity for *your* specific 1991 K5 Blazer, you need to check the following:
* Your vehicle's sticker: Look for a sticker located inside the driver's side doorjamb or the glove compartment. This sticker will list the maximum towing capacity for your vehicle's configuration.
* Your owner's manual: The owner's manual should also specify the towing capacity.
Without this information, providing a reliable towing capacity is impossible. Estimates found online might be wildly inaccurate. Always rely on the information provided by your vehicle's documentation.