Towing ain't the problem. The 4.0L SOHC with the 6-speed and 4.10 gears will pull 3 tons and then some all day long. You can use dual auxillary trans coolers to keep the heat down and a load distributing hitch to make the heavy load spread out more.
The REAL problem is BRAKING and HANDLING with a vehicle that weighs LESS than the trailer you're pulling.
When you get close to the towing capacity, you get what is known as "the tail wagging the dog", where the trailer and the load on it is controlling your vehicle rather than the other way around.
When this happens going down a long mountain road or when you're on a ledge with only a sheet metal guardrail between you and a steep mountainside going down to the valley below, the results can be serious and even fatal.
Even with a towing package, and a trailer brake control, the brakes aren't designed to stop that much weight. Not being able to stop in time can cause you to plow into the back of a vehicle at a stop sign or stoplight and cause an incredible amount of damage when the trailer keeps going and pushing your vehicle with it.
You CAN tow at or even slightly above capacity, but it's best if you only do it sparingly, either to gently tow a boat around a marina parking lot or moving a heavy trailer a few blocks or something. Towing above capacity on a public road puts your life and the lives of others in serious danger if something goes wrong.
Stick with a small trailer and cargo that keeps it under the towing capacity, or get a bigger vehicle to tow with that has a higher towing capacity.