Looking at 04 super duty 5.4 , 3.73 . I have a 27' travel trailer that I'm pulling with an 88 f150 - 5.0 and it struggles pulling it , wondering how well the super duty does

 

The super duty will definitely "handle" it better. It's a beefier, heavier truck throughout.


As far as power, the 5.4, although not the "most" powerful engine out there, is far more powerful than the 5.0 of 1988, which I believe is just over 200HP. The 5.4 in 2004 super duty is the 2 valve version, around 265HP. They went to the 3 valve 5.4 (300HP) in 2005.


4.10 gears in that truck would be ideal, but it should handle it fine as is.