In searching around I've found suggestions that the towing capacity is 5-6,000lbs, with an engine oil cooler, transmission oil cooler, and weight-distributing hitch.
How can I tell if I have these things? And if I don't, what is the towing capacity without those features?
Edit:
I have the 1500 4WD, with 6-lug wheels
According to Trailers.com, the max towing capacity for the 1997 Suburban is:
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.
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:
