According to Trailers.com, the max towing capacity for the 1997 Suburban is:
- 1500 4WD: 6,000lbs
- 1500 2WD: 6,500lbs
- 2500 4WD: 10,000lbs
The way you can tell what equipment came on your vehicle is by looking at the RPO codes which you should be able to find in the glove compartment. Look on the inside of the glove compartment door, there should be a sticker affixed to it with the trucks serial number and then a bunch of three letter codes. The main one you're looking for is the first one here. The other ones should be there if the Z82 is there.
- Z82 : TRAILER PROVISIONS, SPECIAL EQUIPMENT, H.0.
- VR4 : TRAILER HITCH, WEIGHT DISTRIBUTING PLATFORM
- V02 : RADIATOR, HEAVY DUTY, WITH TRANS OIL COOLER
- H05 : AXLE REAR, 3.73 RATIO (Could be GT4) - 1500
- G84 : AXLE REAR, 4.10 RATIO (Could be GT5 or GT8) - 2500
The sticker should look something like this (not exactly like this though ... I just pulled this random image from Google):
I am not able to find anything showing what the towing capacity of the Suburban is without the Z82 package on it. More than likely you won't find the 2500 without the Z82 option as they were meant to be towing beasts. As an educated guess, I'd suggest the following if it doesn't have the HD equipment listed:
- 1500 4WD: 5,000lbs
- 1500 2WD: 5,500lbs
- 2500 4WD: 7,000lbs