The towing capacity of a 1993 K5 Blazer 4x4 with a 350 engine varied depending on several factors including the specific options (like transmission, axle ratio, and whether it had a tow package). You cannot determine the exact towing capacity without checking the original owner's manual or the sticker on the driver's side doorjamb (if still present).
However, a reasonable estimate for a 1993 K5 Blazer 4x4 with a 350 engine and a properly equipped towing package would be in the range of 5,000 to 7,000 pounds. This is just an estimate, and the actual capacity could be higher or lower. Again, consulting the vehicle's documentation is crucial for the accurate figure.