Cliff , Last year I towed my FJ Crusier which wieghts about 6200 lbs . I pulled it with my F150 , I'm guessing the trailer and FJC weight is 8k and I had no trouble . I believe we dropped down to 35 mph going up hwy 111 but it wasn't to bad , alittle nerve racking because it was dark and misting rain . There's only that one real steep part at the begining from what I can remember . Hwy 24 seems like it goes up hill forever but it is alittle better grade . This year I'll have awhole lot lighter load with the 40 . I also purchase a programer for the Ford , not sure if that we'll help or not . But that's my 2 cents for what it's worth .