Something else all need to know.
Cheap sprockets,
are thin & will not have that step up on them to space them on the shaft proper, so some sort of sleeve type spacer will need to be used behind the sprocket over the shaft to space it outward from the cases.
This is not to say cheap sprockets cant be used, just that a spacer is needed to use them.
With out the spacer, the sprocket can move freely on the shaft, wobble in & out, wearing the output shaft more than normal.
Neil