I used to have a '92 F-150 extended cab with the 302 and 4-speed automatic. If I remember correctly, the tow rating of that truck was 7700 lbs. I hauled a late Deere B (around 4400 lbs plus the trailer) 400 miles from Colorado to Kansas without problems but of course that is pretty flat country. The few hills on the trip made the little V8 work pretty hard.
If your truck has a manual transmission the tow rating is much less. A friend had a truck similar to mine with the 5-speed stick and his rating was only about 4000 lbs. Apparently this transmission wasn't up to the constant loads like the auto was.
No matter how much power you have the ability to stop is even more important. Make sure your trailer brakes are fully functional before loading up and hitting the road.