Nope, if you get an F-450 pickup you get the full 440 hp/ 865 tq engine. The F-450 pickup also has a 40,700# GCWR. Dana 130S rear axle and very heavy suspension components. The truck is no taller than an F-350.
I must have been thinking about the f450 cab / chassis. It is the one that is derated.
That is a beautiful truck and looks very capable. For what it is worth the ram 3500 has a 39k GCVWR.