The pedal faces don't require the spacers and the spacers don't require the pedal faces. You can use either independently.

Pedal Faces:
* Less slippy than original pedals when playing in socks
* Can be used with the original m4x8mm countersunk screws. Doesn't require any additional hardware if used without the spacers.

Pedal Spacers:
 * 6 and 12 degree spacers
 * The original metal accelerator pedal requires the 6 degree spacer
 * M4 screws required (at least 8mm in length) to mount the spacer to the Moza unit.
 * There are two options for mounting the pedals to the spacers
   1) Use m4 nuts. You will need to replace the original m4x8mm countersunk screws with m4x15mm countersunk screws.
   2) Use m4 heat inserts. I used 4mm deep inserts, but up to 6mm deep inserts should work as well. You can insert them from the rear. There is a recess to hold the insert in place. Once inserted, run a screw through the front and back to clear out any molten plastic bits. Make sure the mounting face is flat. Trim with a paring knife or sand as needed. If you inserted them crooked, insert a screw half way deep from the front, heat from the rear, use the screw to adjust the angle. 

* Remember, the length of a countersunk screw is measured from the face all the way to the tip of the threads. For other screws, the length is measured from below the head to the tip. The original m4 screws for the pedal faces are 8mm total length, but only about a 6mm threaded length. These are m4x8mm.

Print suggestions:
 * Place them on their sides so you get smooth mating surfaces
 * Print with a brim
 * Use cubic infill
 * At least 1.6mm walls and 30% infill worked well for my ASA filament.
 * On the pedal faces, generate supports touching build plate only and insert support blockers as pictured.

In my photo, I have the 12 degree spacers on the brake and clutch, and the 6 degree spacer on the accelerator. 

Created in Onshape:
https://cad.onshape.com/documents/be87d31655fea8a5a41732dd/w/ee10a3df89c00b70341607f7/e/c9f0cd9ea03081ef77464c57?renderMode=0&uiState=674b84a642bbac411aa8128a