97 ford expedition tow a 27' trailer?

We towed our 27’ Zinger with our 2004 Expedition XLT 5.4 all over the eastern US on long and short trips with no problems. Our son has a Mallard and I expect your trailer will weigh only slightly more than our Zinger. We used WD with 800 lb. bars and dual friction sway control. Dual cam would be better, but I have no experience with it. You can certainly do it with an Expy. I would suggest setting the WD so that the front bumper hooked up is as close as possible to the unhooked height. This insures that the proper weight has been returned to the front axle after hooking up. This will cause the rear to drop several inches, but the Expy is sprung and designed to drop in the rear under load. With your 4 speed transmission the torque converter will run unlocked in fourth gear quite a bit and that generates a lot of heat, the enemy of transmissions. I ran with OD locked out all the time except for occasional downhill runs where I didn’t need the engine braking. When towing I never found any fuel mileage difference between using OD or not—8.5 MPG all the time, and I was much more concerned about burning up the transmission. Of course you will not pull mountains at 60 MPH with a 5.4 but you can pull them in 3rd or 2nd. This engine torque peaks at 2500 rpm which is good for towing.