Hy Roadking53, in those days there was only one length of water pump. In 1958 the front end sheet metal was changed and it became a longer distance from the firewall to the radiator mounting, that is when the radiator shrouds started to be used, I don't remember a spacer for the fan on trucks. On the light trucks I have never seen any factory fan that was anything different than the four blade type, hope that helps.
