Here Recently I had the water pump shaft on my Blazer break. This allowed the fan to bounce around trashing my radiator, Power Steering Pump & pulley, as well as my Crank Pulley. My upper shourd has a hole in it, my lower is mostly gone.
This truck is like some F-bodies. It often sits months with out being started, or if it is, it is not driven or not driven far. Even if your F-body (or other vehicals) do not have mechanical cooling fans, you can suffer the same problem. A problem that comes usually from a vehical sitting. I had the same problem on a 78 Montey Carlo. The car had sat 6 months, then it was brought to me for repair. I got it running after replacing the distributor wires (mouse damage). Was checking that the distributor was getting the advance in at the proper RPM with a hand held tach. At around 3,500 RPM's the shaft snapped. If the hood had been on, I might not be here today. As it was only minor cuts from the fan shroud plastic. That fan went up and landed almost 10 feet away!
So now that spring is here, and your ready for some warm weather crusing in your F-bodies, you might want to spend a few minutes checking some stuff. Remove your belt(s) (it's probably time to change them anyways), and check for noise from the water pump shaft barring. Also feel for bind. If you have a mechanical fan check the clutch hub if so equipped. Make sure the clutch is not lose on the shaft, if it is it needs replaced.
A few hours worth of inspecting can end up saving you a few large in parts. Just a new radiator alone is going to set me back $190 (that's a brand new one with my discount). Charles