I wouldn't pull as is. I have a 4.6 in my Town Car with gears similar to yours and it's fine for daily driving but no way would I tow with it without swapping to 3:55 minimum.
My father in law used his 01 Expedition with 3.31 and a 5.4 ... no heavy duty cooling or trans cooler and he fried his tranny after a few heavy pulls (4-5k) over mountains
I would regear to 3.55 or 3.73 (had 3.55 in my 97 F150 with a 5.4 V8 and it was a good in-between gear) add a stacked plate transmission cooler and use the truck you have.
Thanks!
Jeremiah