I think F450s are about 500 lbs heavier and has different rear springs to haul a fiver better from all I've heard if it has a pickup bed. As you know, I'm also in WA, and my F450 is 14500 GVWR. The previous owner had a farm and registered it commercial. I had that changed since I don't use mine commercially. You can get a 16000 GVWR if you get one without a bed. I assume most of that is the spring pack.
I went with a F450 because they turn super tight, have better brakes, wanted the 19.5s, and I thought I might get a fiver in the future.
