This is easy to print, but quite time consuming and difficult to assemble, and not easily reversible. If you don't have a good reason to prefer this version, go for the one on Thingiverse.

I printed in PLA with 20% infill, which gives something light but
seemingly solid enough. For the E3D-v5, the top remains cool while
printing so I'm not worried about the PLA softening. Other hot-end
designs may require the use of ABS.

You'll need to get a very precise print for this to work well. Test the pieces fit together and slide well on the rods before addings the bearings. You can use between 0 and 4 bearings and it will work. My best results are using two only, the ones furthest from the home position.

The fit to the bearings is tight by design. If you need to customise it, I'll point you to the appropriate pages on TinkerCAD.

Assemble the mount and E3D first. Then, you'll need to take off the right hand side panel, and remove the rods from the drive blocks. Place the fully assembled mount on the intact set of rods, and slide the removed set through the mount and back into the drive blocks. Test the ride is smooth, and when satisfied, reassemble the right side panel.