As to the spare parts I cannot confirm which one I need.
My 1 ton and 2 ton trucks use the exact same rear spring hanger brackets, and all four are the same part, interchangeable. Not sure about a 1/2 ton, but take a look they may be similar, and if so then you can go ahead and get a used one, then decide which location needs it.
If yours is worn enough to make noises, then I would expect you can scrape the grease off and see the slop around the pin, or have someone jack the truck up by the frame while you watch for movement.
Grigg