How big of a TT can an Expedition safely handle?

Towing always seems to be a controversial issue here, and the engineers come out of the woodwork. All I can tell you is that I had a 2000 Expy with a tow package and it handled my 2000 27' Fleetwood Prowler with no issues at all. A little sway with trucks, but had I been concerned I could've added a second anti-sway bar. I'm no longer acquainted with the numbers, but the prowler was no "Lite-weight". Hope that helps.