Towing Capacity Help

[bchamb3]

Ok, if I am asking this in the wrong place, then please direct me to the right place. I also apologize for beating a dead horse.

I have a 1968 GMC Suburban. 1500 1/2 ton with the stock rear end. It is a 12 bolt and I believe I have the 3.07 gears. I am trying to find out the towing capacity of this rear end. (Camping World wants to know this before helping me set up my rig for towing)

I have a 6.0 LS motor and 4l80e tranny. Disc brakes in the front.

I am just trying to get an idea for what my capabilities would be for towing.

Thanks, again!