The V8 trucks, includging the '60-'66 Chevy trucks with the 283 sbc ('60-'66) and the 327 sbc (available in '66), came from the factory with a hard pipe upper radiator hose, with a 4" rubber starter hose at the water inlet and the top tank inlet of the factory Harrison radiator. The factory hose clamps were "tower" clamps manufactured by Wittek or Murray.
I am not sure about the six cylinder equipped trucks, but I would try to do a google search for images of 4-5-6 Chevy trucks, and try to find a good example of some factory spec restorations, showing the engine bay. I have several very nice engine bay shots of six cylinder powerplants. All of them I have seen in pictures or in person are molded rubber hose. If you are interested, let me know and I will e-mail them to you.
Good luck.
