Get the right clock chime block
To get the right clock chime block, the first step is to determine what style chime block is needed. This is where the hammers are located on the clock movement itself.
There are either side, bottom and back strike style clock movements. Chime block style A is for the bottom strike units, and also can be used on the side strike units as well.
The style B is for the side strike units or in some situations the back strike diagonal style Westminster units.
The style C chime block is for floor clock models (and in rare occasions wall clock styles) with two rows of hammers on the back of the clock movement.
With the style clock chime block decided the next step is to count how many rods are needed, and the length off the longest rod measuring through the chime block. Find this information on the corresponding drop down list for the style chime block needed.
If the clock does not sound good, it may not mean you need a new chime block. It could just be a matter of adjusting the hammers to the rods in a better way. This is just done with your fingers bending the wires on the clock that the hammer heads are on. The hammer heads are on wires as they are meant to bent into final position with your fingers. The hammer head should be about 1/8 inch from the rod it is to strike, when at rest. Just bend one at a time and lift and drop to see if you have a nice crisp tone, and do this down the line for each hammer. In the end it will play the song perfect.