F250 w/ 5.4L engine?

I'm looking at downsizing to a smaller engine - going from the diesel to a 5.4L F250 (two motorbikes in back so I need the bigger truck) long-bed, extended cab 4x4. It would have the towing package of course.

Does anyone tow with anything similar? Would you tow across the country (East of the Rockies)? Does it handle eastern mountains okay? I want something that's comfortable when towing at 60-65 MPH. I don't care about mileage (I figure I can do a lot of miles for what I'd save not buying and maintaining a bigger engine). I just don't want to kill the truck!

I did tow with a 4.2L V6 Chevy truck (standard cab, long box, 2x4), and it did okay as far as engine power - I just don't know how much I'm going to lose on a much heavier truck.