towing capacity

I have a towing package on my 1989, 2dr, automatic, 4wd 4 runner, but have never towed anything. My friend thought that I would be able to tow a small horse trailer with one horse in it just around us fine. I was wondering if anyone new how much it is sapposed to be able to haul or what weights other have hauled with theirs. I would greatly appreciate responses. Thanks!!!

well i don't know about automatics. but manuals 22re are rated at 3500 i believe. but i have haulled more then that. like about 4000-4500 or so without too many problems.oh and i had 32 inch tires on lol.just be carefull with the brakes cause they don't respond as well. duh..