I do not use the tanks on my Galaxies and what you will need to convert depends some on what your system looks like now?
You will need a water neck that bolts to the intake where the tank now goes. These can be from a later year car that did not use a tank or they can be purchased on line from places like Rock auto. You will need to know what size thermostat your manifold takes and match the water neck to that size. If you have the large diameter t-stat finding a used water neck will be much harder but early model trucks with FE engines had them so they are out there.
Second, you will have to match up an upper water hose from something, likely from a ford truck.
Third, you will need some place to add water and to check water levels. You can do this in one of several ways. You can buy water necks that have a provision to stack a water cap block on the top or you can get one of the in line hose type but the best is to get a radiator that has a provision for a cap on it. 65 and later usually have this type of radiator.
Scott...