Prusa i3 MK3 * Y-Axis Polymer Bushings/Bearings

I don't like the U-bolt mount for the Y-axis bearings to much.
As one of my bearings startet to make some decent click sounds i desided to give polymer bushings a try.

The number at the end of the STL-filenames (and engraved in the body) indicates the clearance of the bore by a multiple of 0.1mm.
So the bore of e.g. "MK3_spiral_Y_4.stl" has an inner diameter of 8.4mm.
For me No. 2 worked best.