Most people run 1-3 degrees of static caster. For others who are reading this, remember, there is a difference between a 10 degree caster block (active/dynamic caster) and how much actual static caster you choose.
This is an exaggerated 5 full degrees. More than most people use. Click for higher resolution:
Here is 5 degrees with the bottom of the lower arm filed a little bit:
Most of the top oval racers at Snowbirds who use the small springs were using these spring buckets because it's simply smoother. Keeps the spring off of the kingpin in all situations. Less bind. No scratching. It preserves the polishing efforts you've done on your kingpin.