The posts are 74 mm apart on the edge iii and the same on the Floyd. They are the same , where you may have trouble is the routing of the body and the threads on the post screws. If they are fine thread on the Edge 3 you have then you should be okay . If not you will need to replace the bushings that hold the post screws. They come with the tremolo. I just put in a Floyd Rose Special and got rid of the Edge 3 . Mine dropped in with no probs. Feels so much more stable and solid.