Definitely different on pickups. Rear bumper is very flat and just curve in slightly on the ends. Front has more of a arc to it with curled in ends. I believe the panel trucks used the same front bumper also in the rear. Its hard to tell looking at them sometimes but they are actually very different when bolted on. I dont see you being able to get it on the truck if its the wrong bumper. The thing is like a big leaf spring and it just wants to stay where its at when you try flexing it.
Heres my 150 for reference. I could never find good pics online to really see the shapes so hope this helps you.
