Set the truck on jack stands, on a level floor. Measure frome the floor to the frame at different points, under the cab, the crossmember, frame ends ect. Take an "X" measurement in same areas, to determine if the frame is diamond. From your description sounds like the frame has some damage, but it can be fixed. I would doubt if there's that much adjustment in the radiator support. Most shop manuals have the frame measurements. Frames can be bent 6 different ways, Sway, Sag, Mash, Twist, Diamond and Buckled. Hope yours isn't to serious.
