Danny,
It looks like you have a long-shaft water pump. The first thing you might be interested in doing is to identify the year f you engine. It is not a 1954 261.
The 55-2nd through 1963 235/261 water pump will not allow enough space for the fan to be mounted; and, the location of the 55-63 fan is not ideal.
The relocation adapter-plate (mentioned above by Virginiafiretruck" will allow a 1955-1st or earlier water pump to be used. This will (1) put the fan in the correct location, (2) the older pump will have the correct pully size, and (3) you would be able to choose a pump that has a pulley with the correct groove=width to match the grooves in your harmonic balancer's and alternator's pulleys.
If you just want to change your pulley, maybe someone will post information on where to find a pulley, and how to remove the existing pulley, and how to press on the "new" pulley in the correct location, and how to trim the excess material off the pulley-post.
Tim
