I had over-looked the fact that this kit was meant for an Ender 3 Pro with a 4040 Extrusion on the Y plane. The belt-drive does not at all function as intended, and after 3 days of modding I gave up on the belt. 

So please note, if you intend to stay with the belt drive, you will need to purchase a proper extrusion and tap it out to fit the Ender 3. 

Otherwise, you can use the dual z bracket to drive the y axis with a lead screw.