If you have an aluminum spinner you don't have to worry about this, but if you have a carbon fiber spinner you'll have to watch your alignment.

Make sure you match up your spinner backplate and if the holes are already cut in the spinner you'll have to align the prop so it will fit between the tabs that the spinner screws onto. Take care to align everything so the prop does not touch the CF spinner cone after it is mounted.

I chose a CF spinner because it has less mass, allowing my motor to spool up more quickly, and it gave me perfect balance since I used a CF stabilizer tube and CF tailwheel.