I remembered buying the 10K pulley upgrade from Mike of SG Tooling several years ago and started digging through the boxes. Found it still wrapped up in plastic in the box. After reading through the installation guide many times, I proceeded to put it on the machine.
Let me leave you with this video of the spindle running up to its max speed, whatever it is, since I didn't adjust the spindle preload and have no way to test. Click here to view on YouTube: Sherline 10k RPM Pulley in operation
Have a blessed week folks!