The spring sits down around a piece of flat steel. When you move the shifter side to side, one side of the spring actuates on the piece of steel, while the other side moves with the shifter lever mechanism. In the picture above there is a cutout that has been circled. This cutout allows the spring to move in the full range of motion. In order to accomodate the taller plate that cutout needs to be extended upwards.
I will include a paper template with the riser plate that can be used to mark and cut the slot.
Hope that helps
Paul