I just happen to have the sales brochure from '93 for the T100 (should be the same for the '94 model year also). Here is what it says about towing capacities:

Gross Vehicle Weight Rating: 2WD 1/2 Ton: 5000 lbs., 2WD 1 Ton: 6000 lbs. , 4WD 1/2 Ton: 5500 lbs.

TOWING CAPACITY: 2WD 1/2 Ton 5000 lbs., 2WD 1 Ton 5000 lbs., 4WD 1/2 Ton 4500 lbs.

Gross Combination Weight Rating: 2WD 1/2 Ton: 9000 lbs., 2WD 1 Ton: 9000 lbs., 4WD 1/2 Ton: 9000 lbs.

There is a note about the towing capacity requiring a Class III tow hitch accessory. So if you need to tow, the Class III receiver would be the best way to go. HTH

I would agree with Erik about the add-a-leaf or air bags as being the best way to beef up the load capacity of the rear suspension. These trucks are known for the rear leafs getting a little weak (overtime) and causing the sagging rear issue. It doesn't take much of a load to be on the bump stops.