The 400 Cat should be able to do the job. Going up steep hills you will probably still have some high revs but not as bad as the 460 was.
You might have a problem with your Ford Fusion though depending on which transmission you have. The link below is pretty accurate but check your manual and see what Ford says about towing it.
Application Charts | Remco Towing
Jon & Sue Francis (Retired U.S.A.F.)
Lil Girl-Rescued, Abby Rescued, Peaches Rescued
06 Allegro 35TSA Workhorse Chassis
2013 Chevy Spark Dinghy