Depending on your axle ratio, you may find a 2,000-4500lb towing capacity. However with a manual transmission its legally rated to only tow 2,000lbs. As far as payload a lot of that will depend on how worn out your suspension components are.
I had 557lbs in my 87 Ranger last weekend hauling a load of scrap to the recycler....truck handled it without any issues, no sag in the rear, and really couldn't tell I had anything back there which I wouldn't think so at only 557lbs it shouldn't make a huge difference in a truck that doesn't have worn out suspension components and a properly running engine only issue I still have is it cuts out at higher speeds randomly. However, if the truck is running right, I wouldn't be surprised to see a 1,000lb load in the bed of a Ranger and it handle the load fine. Stopping is the biggest problem. The brakes are ok, but all that weight is really taxing them to death...for towing, anything over about 2,000lbs needs trailer brakes, its cheap insurance anyways, the more brakes you got the better your stopping power, who cares how well and how fast your truck can get a trailer moving, if it doesn't have the ability to safely slow it down and stop it.
When I got my Ranger I really wanted to install a receiver hitch and tow a small travel trailer, but after finding out it really only has a 2k towing capacity it don't leave much for trailer options...I may use it to tow a little 4x8 trailer but that would be about it.